Diversity and Local Uses of the Convolvulaceae Family in Udon Thani Province, Thailand, with Notes on Its Potential Horticultural Significance

Abstract

This study investigates the species diversity of the Convolvulaceae family in Udon Thani Province, Thailand, and was conducted from January to December 2022. A total of 52 species across fifteen genera were identified. Ipomoea was the most diverse genus in the region. The Ipomoea family was found in five ecological areas: deciduous dipterocarp forests, mixed deciduous forests, aquatic areas, open areas and roadsides, and cultivated areas like home gardens. Most species flower during the rainy season, especially from June to August, while some bloom in the winter, around January to March. Out of the total number of species, 29 were evaluated as rare and 23 as common. Meanwhile, 44 species were proposed for conservation as Not Evaluated and six species as Least Concern. Traditional uses of these species include food, animal fodder, horticultural cultivation, medicinal plants, and ornamental plants. The whole plant is the most used part followed by leaves, stems, roots or storage roots, and inflorescence, respectively. This research contributes valuable data on the biodiversity, conservation status, and cultural significance of Convolvulaceae species in Udon Thani Province, offering a foundation for future studies and potential sustainable resource management.

1. Introduction

Thailand is renowned for its biodiversity, attributed to its tropical location, diverse ecosystems, and unique topography. The country’s varied landscape includes coastal areas, floodplains, mountains, and dense forests, which support a wide range of plant and animal species [1]. As one of the world’s most biodiverse countries, Thailand is home to approximately 15,000 plant species [2]. Extensive forest cover provides vital resources such as food, medicinal plants, timber, and cultural artifacts, which are crucial to both local communities and the ecological balance of the region [3].

The Udon Thani Province, located in northeastern Thailand, features a landscape of low hills, plains, and remnants of deciduous dipterocarp forests. Despite its rich biodiversity, the province has experienced significant deforestation and habitat loss due to agricultural expansion and urbanization. These environmental pressures have led to the destruction of natural habitats, affecting the plant and animal populations that rely on them [4]. Nevertheless, Udon Thani remains a key region for plant diversity, particularly in protected areas such as Phu Phra Bat Historical Park and Phu Foi Lom. These zones preserve various native plant species, providing critical refuges for biodiversity amidst ongoing threats [5,6].

Local communities in Udon Thani have long relied on the region’s biodiversity for various purposes, including traditional cuisine, herbal medicine, cosmetics, dyes, building materials, and religious ceremonies [7]. Indigenous knowledge of local plants promotes the sustainable use of natural resources, highlighting the deep connection between people and the forest, which is strongly tied to the lifestyles and local cultures from generations of coexisting with that ecosystem [8]. In this context, biodiversity not only sustains local livelihoods but also preserves cultural heritage [9]. Research on plant diversity in community forests helps promote conservation awareness and supports sustainable resource management while educating future generations on ecosystem preservation [10].

Among Thailand’s diverse plant families, Convolvulaceae Juss. stands out for its ornamental and ecological value. The family consists of approximately 55 genera and 1930 species [2], predominantly distributed in tropical regions, with the highest diversity found in tropical America and Asia [2]. Notable, the research conducted by Judd et al. [11] identifies the primary genera in this family such as Ipomoea L. (600 species), Convolvulus L. (250 species), Cuscuta L. (150 species), and Jacquemontia Choisy (120 species). In Thailand, the family is represented by various genera, e.g., Na Songkhla and Khunwasi [12] examined 10 genera, 26 species, and one variation of the Convolvulaceae family in Thailand. Khunwasi et al. [13] conducted a comprehensive study on the taxonomy of 27 species and one variant of Argyreia Lour. in Thailand. Furthermore, Saensouk [14] found five genera and 25 species of Convolvulaceae in the Muang District of Nong Khai Province. Another work in That Phanom District, Nakhon Phanom Province, reported eight genera and 28 species [15].

In Thailand’s forests, Convolvulaceae species are primarily climbing plants or herbaceous ground flora, forming a crucial part of the understory [16]. Many species are uncommon and face threats from habitat destruction, particularly due to deforestation, agricultural expansion, and urbanization [17]. Despite their ecological importance, these species are often understudied, leading to gaps in knowledge regarding their roles in local ecosystems [18]. Furthermore, Ipomoea species are of economic value, particularly as ornamental plants and for their medicinal properties [19]. However, the full extent of Convolvulaceae diversity in Thailand, especially in underexplored regions such as Udon Thani, is not well documented.

This study aims to document the species diversity and local uses of Convolvulaceae in Udon Thani Province, a region where plant diversity remains insufficiently explored. By providing a comprehensive overview of Convolvulaceae species, this research contributes to a deeper understanding of their ecological roles and their significance in traditional and local practices. Such information is essential for developing sustainable management strategies that ensure the conservation and continued utilization of these plant resources [20].

In addition to cataloging species diversity and ethnobotanical uses, this study also examines the horticultural potential of Convolvulaceae species. Certain members of this family exhibit desirable ornamental traits and adaptability, making them valuable for horticultural applications. By highlighting their aesthetic and functional attributes, this research aims to support future efforts in integrating native Convolvulaceae into horticulture while reinforcing conservation initiatives. Ultimately, these findings provide critical insights into the ecological, cultural, and economic importance of Convolvulaceae in Udon Thani Province.

2. Materials and Methods

2.1. Plant Material and Diversity Study

Field exploration was conducted between January and December 2022 in Udon Thani Province, Thailand (Figure 1), to collect voucher specimens of the Convolvulaceae family from 20 sample sites per district. Various species were collected from each site, and for each species, one specimen was selected as the reference voucher specimen, as cited in

Table 1. The diversity of Convolvulaceae species in Udon Thani Province, along with their local name, habits, distribution, ecology, phenology, conservation status, utilization, part uses, CI, and specimen voucher.

No.	Species	Local Name	Habits	Distribution (Districts)	Ecology	Phenology	Conservation Status			Utilization	Used Parts	CI	Collection No.
							By Authors	POWO	IUCN
1.	Aniseia martinicensis (Jacq.) Choisy	Jing Jor Khaow	Herbaceous vines, aquatic or semi-aquatic	Muang, Kumphawapi, Nong Han, Sang Khom	AA, RD	Flowering: May–September Fruiting: September–October	Rare	Introduced	LC	AF, MD	LVs, SMs, RSs, WP	0.65	CU001
2.	Argyreia breviscapa (Kerr) Ooststr.	Tao Fa Ra Ngub	Woody vines	Ban Phue, Ban Dung, Pen, Nong Saeng, Wang Sam Mo	DDF	Flowering: June–August Fruiting: August–October	Rare	Native	NE	AF, MD	SMs, RSs, WP	0.73	CU002
3.	Argyreia capitiformis (Poir.) Ooststr.	Fon Saen Ha	Woody vines	All districts	DDF, MDF	Flowering: July–August Fruiting: September–October	Common	Native	NE	AF, MD	LVs, SMs, WP	0.60	CU003
4.	Argyreia collinsiae (Craib) Na Songkhla & Traiperm	Pak Bung Chang	Woody vines	Ban Phue, Ban Dung, Pen, Nong Saeng, Wang Sam Mo	DDF	Flowering: May–July Fruiting: July–October	Rare	Native	NE	AF, MD, ON	FSs, IR, LVs, SMs, RSs, WP	1.03	CU004
5.	Argyreia kerrii Craib	Khruea Phu Muang	Woody vines	Ban Dung, Ban Phue, Pen, Nong Saeng, Wang Sam Mo	MDF	Flowering: May–July Fruiting: July–October	Rare	Native and endemic species	NE	AF, ON	WP	0.70	CU005
6.	Argyreia lanceolata Choisy	Muang Phu Phra Bat	Woody vines	Ban Phue	DDF	Flowering: June–August Fruiting: July–October	Rare	Native	NE	AF, MD, ON	WP	0.85	CU006
7.	Argyreia laotica Gagnep.	Khruea Khao Long	Woody vines	Ban Phue, Nam Som, Na Yung	DDF	Flowering: June–July Fruiting: July–October	Rare	Native	NE	AF, MD, ON	WP	0.70	CU007
8.	Argyreia leucantha Traiperm & Staples	Jing Jor Khon Dok	Woody vines	Ban Dung, Ban Phue, Pen, Nong Saeng, Wang Sam Mo	DDF	Flowering: May–July Fruiting: July–October	Rare	Native and endemic species	NE	AF, ON	WP	0.55	CU008
9.	Argyreia mollis (Burm.f.) Choisy	Khruea Phu Ngoen	Shrubs	All districts	DDF	Flowering: May–July Fruiting: July–October	Common	Native	NE	MD, ON	LVs, RSs, WP	0.63	CU009
10.	Argyreia nervosa (Burm.f.) Bojer	Bai Ra Bard	Woody vines	All districts	CV	Flowering: January–December Fruiting: January–December	Common	Introduced	NE	HC, MD, ON	LVs, RSs, WP	0.93	CU010
11.	Argyreia osyrensis (Roth) Choisy	Kamlang Moo Thuean	Woody vines	Ban Phue, Ban Dung, Pen, Nong Saeng, Wang Sam Mo	DDF, MDF, CV	Flowering: May–July Fruiting: July–October	Rare	Native	NE	AF, HC, MD	LVs, WP	0.80	CU011
12.	Argyreia splendens (Hornem.) Sweet	Tao Wan Long	Woody vines	Ban Phue	DDF, CV	Flowering: August–November Fruiting: September–December	Rare	Native	DD	HC, MD, ON	LVs, WP	0.85	CU012
13.	Camonea bambusetorum (Kerr) A.R.Simões & Staples	Jing Jor Nuan	Herbaceous vines	Ban Phue, Nam Som, Na Yung	DDF, MDF, RD	Flowering: January–March Fruiting: March–April	Rare	Native	NE	AF, MD	LVs, RSs, WP	0.70	CU013
14.	Camonea kingii (Prain) A.R.Simões & Staples	Jing Jor Doi	Herbaceous vines	Ban Phue, Nam Som, Na Yung	DDF	Flowering: January–March Fruiting: March–April	Rare	Native	NE	AF, MD, ON	WP	0.85	CU014
15.	Camonea umbellata (L.) A.R.Simões & Staples	Jing Jor Khaow	Herbaceous vines	All districts	DDF, RD	Flowering: January–March Fruiting: March–April	Common	Native	NE	AF, MD, ON	FSs, LVs, SMs, RSs, WP	1.03	CU015
16.	Decalobanthus mammosus (Lour.) A.R.Simões & Staples	Sa Si Thon	Herbaceous vines	Ban Dung, Ban Phue	AA, DDF, MDF, RD	Flowering: October–December Fruiting: November–January	Rare	Native	NE	AF	WP	0.38	CU016
17.	Distimake cissoides (Lam.) A.R.Simões & Staples	Jing Jor	Herbaceous vines	Kumphawapi, Muang, Non Sa-at	AA	Flowering: July–August Fruiting: August–September	Rare	Introduced	NE	AF, MD	RSs, WP	0.63	CU017
18.	Distimake quinatus (R.Br.) A.R.Simões & Staples	Jing Jor Nio Nang	Herbaceous vines	Ban Phue, Nam Som, Na Yung, Sang Khom, Wang Sam Mo	DDF	Flowering: October–December Fruiting: November–January	Rare	Native	NE	AF	WP	0.38	CU018
19	Distimake vitifolius (Burm.f.) Pisuttimarn & Petrongari	Jing Jor Lueang	Herbaceous vines	All districts	DDF, MDF, RD	Flowering: January–March Fruiting: March–April	Common	Native	NE	AF, ON	WP	0.70	CU019
20.	Evolvulus alsinoides (L.) L.	Bai Tor Kan	Prostrate or creeping herbs	Ban Phue, Nong Saeng, Wang Sam Mo	DDF, RD	Flowering: June–August Fruiting: July–September	Rare	Native	NE	AF, MD, ON	WP	0.73	CU020
21.	Evolvulus glomeratus Nees & Mart.	Far Pra Dit	Prostrate or creeping herbs	Muang, Nong Saeng, Wang Sam Mo	CV	Flowering: June–August Fruiting: July–September	Rare	Introduced	NE	HC, ON	WP	0.70	CU021
22.	Evolvulus nummularius (L.) L.	Bai Tang Rian	Prostrate or creeping herbs	All districts	CV, RD	Flowering: June–October Fruiting: August–November	Common	Introduced	NE	AF, HC, MD, ON	WP	1.18	CU022
23.	Hewittia malabarica (L.) Suresh	Jing Jor Lek	Herbaceous vines	Pen, Sang Khom	AA, CV, RD	Flowering: June–August Fruiting: July–September	Rare	Native	NE	HC, MD	LVs, WP	0.50	CU023
24.	Ipomoea alba L.	Chom Chan	Herbaceous vines	All districts	CV	Flowering: June–September Fruiting: September–October	Common	Introduced	LC	AF, FDs, HC, MD, ON	IR, LVs, WP	1.35	CU024
25.	Ipomoea aquatica Forssk.	Phak Bung	Herbaceous vines, aquatic plant	All districts	AA, CV	Flowering: January–March Fruiting: March–April	Common	Native	LC	FDs, HC MD, ON	LVs, SMs, WP	0.85	CU025
26.	Ipomoea asarifolia (Desr.) Roem. & Schult.	Pak Bung Khan	Herbaceous vines	Ban Phue, Muang, Pen	AA, CV, RD	Flowering: January–March Fruiting: March–April	Rare	Native	NE	HC, FDs, MD	LVs, RSs, SMs, WP	1.35	CU026
27.	Ipomoea batatas (L.) Lam.	Man Thet	Herbaceous vines	All districts	CV	Flowering: January–March Fruiting: March–April	Common	Introduced	DD	AF, HC, FDs, MD	LVs, RSs, SMs, WP	1.93	CU027
28.	Ipomoea cairica (L.) Sweet	Pak Bung Rua	Herbaceous vines	All districts	CV, RD	Flowering: January–March Fruiting: March–April	Common	Native	LC	HC, MD	FSs, LVs, RSs, WP	1.18	CU028
29.	Ipomoea carnea Jacq.	Pak Bung Fa Rung	Shrubs, semi-aquatic	All districts	CV	Flowering: January–December: Fruiting March–December	Common	Introduced	NE	AF, MD, ON	RSs, WP	0.83	CU029
30.	Ipomoea campanulata L.	Thao Phan En	Herbaceous vines	Ban Phue, Nam Som, Na Yung	DDF, MDF	Flowering: June–September Fruiting: September–October	Rare	Native	NE	AF, ON	WP	0.68	CU030
31.	Ipomoea coptica (L.) Roth	Pak Bung Rua Dok Khaow	Prostrate or creeping herbs	Ban Phue, Nam Som, Na Yung	DDF, MDF	Flowering: June–September Fruiting: September–October	Rare	Native	LC	MD, ON	WP	0.55	CU031
32.	Ipomoea holubii Baker	Pak Bung Khot	Herbaceous vines	Ban Phue	RD	Flowering: July–September Fruiting: September–October	Rare	Introduced	NE	AF	WP	0.35	CU032
33.	Ipomoea nil (L.) Roth	Wan Pak Bung	Herbaceous vines	All districts	DDF, MDF, RD	Flowering: June–September Fruiting: September–October	Common	Introduced	NE	AF, MD, ON	FSs, LVs, RSs, WP	1.13	CU033
34.	Ipomoea obscura (L.) Ker Gawl.	Tong Wa	Herbaceous vines	All districts	DDF, MDF, RD	Flowering: June–September Fruiting: September–October	Common	Native	NE	AF, MD, ON	FSs, LVs, WP	1.45	CU034
35.	Ipomoea pes-tigridis L.	Khayum Teen Mha	Herbaceous vines	All districts	DDF, MDF, RD	Flowering: June–September Fruiting: September–October	Common	Native	NE	AF, MD, ON	FSs, LVs, RSs, WP	0.95	CU035
36.	Ipomoea pileata Roxb.	Thao Song Salueng	Herbaceous vines	Ban Phue, Nam Som, Na Yung, Nong Saeng, Wang Sam Mo	DDF, MDF, RD	Flowering: June–September Fruiting: September–October	Rare	Native	NE	AF, MD, ON	LVs, RSs, WP	0.95	CU036
37.	Ipomoea purpurea (L.) Roth	Dok Pak Bung	Herbaceous vines	All districts	CV	Flowering: January–December Fruiting: March–December	Common	Introduced	NE	AF, MD, ON	LVs, WP	0.73	CU037
38.	Ipomoea quamoclit L.	Khon Sawan	Herbaceous vines	All districts	DDF, CV, MDF, RD	Flowering: June–September Fruiting: September–October	Common	Introduced	NE	HC, MD	FSs, LVs, SMs, WP	0.50	CU038
39.	Ipomoea sagittifolia Burm.f.	Sa-uek	Herbaceous vines	Ban Phue, Nam Som, Na Yung, Nong Saeng, Wang Sam Mo	DDF, MDF	Flowering: June–September Fruiting: September–October	Rare	Native	NE	MD, ON	LVs, WP	0.68	CU039
40.	Ipomoea triloba L.	Jing Jor Dok Khon	Herbaceous vines	All districts	DDF, MDF, RD	Flowering: June–September Fruiting: September–October	Common	Introduced	NE	AF	WP	0.18	CU040
41.	Jacquemontia paniculata (Burm.f.) Hallier f.	Jing Jor Phi	Herbaceous vines	Muang, Pen, Sang Khom	AA, DDF, RD	Flowering: June–August Fruiting: July–September	Common	Native	NE	ON	WP	0.35	CU041
42.	Lepistemon binectarifer (Wall.) Kuntze	Yan Khon	Herbaceous vines	Ban Phue, Nam Som, Na Yung	DDF, MDF, RD	Flowering: January–December Fruiting: March–December	Rare	Native	NE	AF, ON	WP	0.55	CU042
43.	Merremia gemella (Burm.f.) Hallier f.	Thao Sa-uek Yai	Herbaceous vines	Ban Phue, Kumphawapi, Nam Som, Na Yung, Nong Han, Nong Saeng, Muang, Pen, Sang Khom, Wang Sam Mo	AA, DDF, MDF, RD	Flowering: October–December Fruiting: November–January	Common	Native	NE	AF, MD, ON	LVs, WP	0.70	CU043
44.	Merremia hederacea (Burm.f.) Hallier f.	Thao Sa-uek	Herbaceous vines	All districts	AA, DDF, MDF, RD	Flowering: October–December Fruiting: November–January	Common	Native	NE	AF, MD, ON	LVs, WP	0.80	CU044
45.	Merremia hirta (L.) Merr.	Jing Jor Nuan Lek	Herbaceous vines, semi-aquatic	Ban Dung, Ban Phue, Nam Som, Na Yung, Pen, Sang Khom	AA, DDF, MDF, RD	Flowering: October–December Fruiting: November–January	Rare	Native	NE	AF, MD, ON	WP	0.75	CU045
46.	Merremia thorelii (Gagnep.) Staples	Jing Jor Bai Khon	Herbaceous vines	Ban Phue, Nam Som, Na Yung, Nong Saeng, Wang Sam Mo	DDF, MDF, RD	Flowering: October–December Fruiting: November–January	Rare	Native	NE	AF, MD, ON	WP	0.68	CU046
47.	Merremia verruculosa S.Y.Liu	Jing Jor Hin	Herbaceous vines	Ban Phue, Nam Som, Na Yung, Sang Khom, Wang Sam Mo	DDF	Flowering: October–December Fruiting: November–January	Rare	Native	NE	AF, MD, ON	WP	0.78	CU047
48.	Operculina petaloidea (Choisy) Ooststr.	Ban Bai	Herbaceous vines, semi-aquatic	Ban Dung, Ban Phue, Muang, Nam Som, Na Yung, Pen, Sang Khom	AA, RD	Flowering: January–December: Fruiting March–December	Common	Native	LC	AF, MD, ON	WP	0.70	CU048
49.	Operculina turpethum (L.) Silva Manso	Jing Jor Liam	Herbaceous vines, semi-aquatic	Ban Dung, Ban Phue, Muang, Nam Som, Na Yung, Pen, Sang Khom	AA, RD	Flowering: January–December Fruiting: March–December	Common	Native	NE	AF, MD, ON	RSs, SMs, WP	1.18	CU049
50.	Porana volubilis Burm.f.	La da Wan	Woody vines	All districts	CV	Flowering: October–December Fruiting: November–January	Common	Native	NE	MD, ON	FSs, IR, RSs, SMs, WP	0.93	CU050
51.	Rivea ornata (Roxb.) Choisy	Ban Kham	Woody vines	Nong Saeng, Wang Sam Mo	DDF	Flowering: June–September Fruiting: September–October	Rare	Native	NE	MD, ON	LVs, WP	0.55	CU051
52.	Xenostegia tridentata (L.) D.F.Austin & Staples	Jing Jor Rang Hae	Herbaceous vines	Ban Phue, Nong Saeng, Wang Sam Mo	DDF	Flowering: October–December Fruiting: November–January	Rare	Native	NE	AF, MD, ON	WP	0.60	CU052

Abbreviations: Ecology: aquatic area (AA); cultivated (CV); deciduous dipterocarp forest (DDF); mixed deciduous forest (MDF); and roadside, open area (RD). Conservation status: Data Deficient (DD); Least Concern (LC); and Not Evaluated (NE). Utilization: animal fodder (AF); horticultural cultivation (HC); foods (FDs); medicinal (MD) plants; and ornamental (ON) plants. Part uses: fruits and seeds (FSs); inflorescences (IR); leaves (LVs); stems (SMs); storage roots or roots (RSs); and whole plant (WP).

. The specimens were identified through morphological comparisons with established references, e.g., Flora of Thailand Volume 10, Part 3 [21], Flora of China Volume 16 [22], and Plants of the World Online [2]. Additional cross-referencing was conducted using specimens from herbaria, such as the Department of National Parks, Wildlife and Plant Conservation (BKF), Bangkok Herbarium (BK), Khon Kaen University Herbarium (KKU), and Queen Sirikit Botanical Gardens Herbarium (QBG), as well as digital images from Kew’s Herbarium and the Kew Science website. Field data on species diversity, local names, ecological information, distribution, and phenology were also recorded. The morphological characteristics of the specimens were examined using a stereoscopic microscope (Stemi 2000-C, Zeiss, Oberkochen, Germany) and measured with rulers and Vernier calipers for accurate documentation. A comprehensive review of primary taxonomic literature and major research databases, including Scopus, Web of Science, and Google Scholar, was also conducted. All specimens were deposited at the Vascular Plant Herbarium, Mahasarakham University (VMSU), Maha Sarakham Province, Thailand, and the conservation status of each species was proposed according to the IUCN Red List Criteria [23].

2.2. Traditional Uses Study

Data on the utilization of plants were collected through structured interviews with 60 randomly selected villagers residing near the sample sites. Participants, with an equal number of male and female respondents, were first informed about this study’s objectives and the voluntary nature of their participation. Informed consent was obtained before conducting the interviews. The data collection process was divided into two key phases.

Initially, a survey on plant diversity was conducted in the study area to compile a list of species present along with photographs. This list formed the basis for the subsequent interviews. During the interviews, participants were asked whether they knew each species from the diversity list. If a participant was familiar with a species, further questions were posed to gather information about the local name, the plant parts used, and the applications (e.g., medicinal, culinary, or cultural uses) of the species. In cases where the participant did not recognize a particular species, the interview proceeded with the next species on the diversity list.

To assess the economic value of plant species, price data were also collected from some of the informants who were local vegetable vendors. These informants, who cultivated these plants for sale, provided information on the market prices of various species. Data collection occurred at four-month intervals throughout the year (January to December 2022).

This approach ensured a comprehensive understanding of the species’ traditional knowledge and economic value while maintaining the focus solely on plant-related information. Ethical considerations were adhered to and no personal data were collected, which meant that formal ethics approval was not required.

2.3. Conservation Status Study

A comprehensive investigation was conducted on the endemic species of the Convolvulaceae family in Udon Thani Province, utilizing data from the Plants of the World Online (POWO) database [2] to determine whether species are native, introduced, or endemic. This study aimed to identify and document species restricted to the local flora, enhancing the understanding of regional endemism within the Convolvulaceae family.

Conservation Status in the Study Area: The conservation status of Convolvulaceae species within the designated geographical area was systematically evaluated using data collected during extensive field investigations. Species were classified into categories based on their population densities and distribution within the study site and subsequently labeled as either “common” or “rare”. This localized assessment provides critical insights into the current status and potential vulnerabilities of the regional flora.

Global Conservation Status: A further assessment of the conservation status of Convolvulaceae species in Udon Thani Province was performed in alignment with the IUCN Red List criteria [23]. This study incorporated global data from the IUCN database, enabling a comparative analysis of local findings within a broader global conservation framework. This approach offers a dual perspective on species’ conservation needs, integrating both local and international conservation priorities.

2.4. Data Analysis

2.4.1. Cultural Importance Index (CI)

The CI assesses the local significance of a particular plant. It varies by classifying usage data into categories according to the type of use. This approach helps identify plant species that hold importance in different utilization contexts [24]. The CI was computed using the following formula:

$$\mathrm{CI} =\sum _{\mathrm{u}={\mathrm{u}}_1}^{{\mathrm{u}}_{\mathrm{NC}}}\sum _{\mathrm{i}={\mathrm{i}}_1}^{{\mathrm{i}}_{\mathrm{NC}}}{\displaystyle \frac{\mathrm{U}{\mathrm{R}}_{\mathrm{ui}}}{\mathrm{N}}}$$

(1)

where

• CI = The Cultural Significance Index of the plant;
• UR_ui = The report on the usage of a specific utilization group;
• I = The total count of plant groups sorted by usage type;
• NC = The total number of utilizations;
• N = The total number of respondents.

2.4.2. Informant Agreement Ratio (IAR)

The Informant Agreement Ratio (IAR) is a metric used to evaluate the degree of agreement among informants about the use of local vegetable species for treating particular diseases. The IAR is calculated with the following formula [25]:

$$\mathrm{IAR}={\displaystyle \frac{{\mathrm{N}}_{\mathrm{ur}}-{\mathrm{N}}_{\mathrm{t}}}{{\mathrm{N}}_{\mathrm{ur}}-1}}$$

(2)

where

• IAR = The Informant Agreement Ratio;
• N_ur = The total number of use reports for a specific disease category;
• N_t = The number of species reported for that category.

The IAR reflects the level of consensus among informants regarding the selection of local vegetable species for treating diseases. A high IAR value, close to 1, indicates strong agreement, meaning commonly accepted species are preferred for their recognized effectiveness. In contrast, a low IAR value, near 0, suggests weak agreement, implying that species are chosen arbitrarily or with little consensus for treating the disease.

2.4.3. Fidelity Level (FL)

The Fidelity Level (FL) is a metric that measures the extent to which a particular plant species is preferred for treating a specific disease. It identifies the plant species most frequently used for a particular condition. The FL percentage is calculated using the following formula [26]:

%FL = (N_p/N_t) × 100

(3)

where

• FL = The Fidelity Level;
• N_p = The number of times a specific plant is reported for treating a given disease;
• N_t = The total number of reports for that plant species across all diseases.

2.4.4. The Economic Value of Convolvulaceae (EVC)

To assess the economic value of Convolvulaceae in Udon Thani Province, the following formula was used:

EVC = AP × SM × SP

(4)

where

• AP = The average price of the Convolvulaceae (THB/plant);
• SM = The total monthly quantity of Convolvulaceae sold by traders (in number of plants);
• SP = The total number of months during which local vegetables are sold in the year.

The EVC represents the overall value of Convolvulaceae traded throughout the year. In other words, it indicates the annual income that traders earn from selling each type of Convolvulaceae [26].

2.4.5. Jaccard Similarity Index (JI)

To assess species diversity across thirteen districts, we employed the Jaccard Similarity Index (JI), a widely used tool for comparing the similarity between two data sets [27]. In this study, the JI was applied to evaluate the similarities in species composition across the districts. The formula for calculating JI is as follows:

$$\mathrm{JI}={\displaystyle \frac{\mathrm{a}}{\mathrm{a}+\mathrm{b}+\mathrm{c}}}$$

(5)

where

• a = The number of species common to both districts;
• b = The species found only in the first district;
• c = The species present solely in the second district.

This index allowed us to quantify species diversity and provide an objective comparison of the ecological compositions between districts. It offered valuable insights into the degree of similarity or difference in species presence, thereby improving our understanding of biodiversity patterns in the study area.

Furthermore, the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) was used to examine the similarity in species diversity between districts. The Jaccard Similarity Index was applied to quantify shared species between each district pair, with the resulting similarity matrix serving as input for the UPGMA algorithm. The clustering and dendrogram construction were carried out using Past4 software version 4.15 [27]. The resulting dendrogram visually represents the hierarchical clustering of districts based on species composition, revealing their ecological relationships and highlighting clusters with similar biodiversity profiles.

3. Results

3.1. Diversity of Convolvulaceae Family from Udon Thani Province

This study identified 15 genera and 52 species (as detailed in Table 1 and Figure 2, Figure 3 and Figure 4). The most diverse genus was Ipomoea, represented by 17 species. The second most diverse genus was Argyreia, with 12 species, followed by Merremia with five species. Camonea, Distimake, and Evolvulus each had three species. Operculina was represented by two species. Several genera, including Aniseia Choisy, Decalobanthus, Hewittia, Jacquemontia, Lepistemon, Porana, Rivea, and Xenostegia, were represented by only one species each.

3.2. Life Forms of Convolvulaceae Family in Udon Thani Province

The Convolvulaceae family in Udon Thani exhibits diverse growth habits, reflecting their ecological adaptability across various habitats (Table 1). Herbaceous vines represent the most common growth form, with Ipomoea species such as I. alba, I. cairica, and I. triloba predominantly observed twining or trailing over surfaces in disturbed areas, roadsides, wetlands, and horticultural fields.

Woody vines are also well represented, with 11 species of Argyreia, along with Porana and Rivea, frequently recorded in forested and scrubland areas where they climb trees and shrubs for support. Shrub-like forms, such as Ipomoea carnea and Argyreia mollis, exhibit woody stems that either support climbing growth or develop into low, bushy structures.

Prostrate or creeping herbs, including Evolvulus alsinoides, E. glomeratus, and E. nummularius, are primarily found spreading across grasslands and open areas.

Meanwhile, aquatic and semi-aquatic species such as Aniseia martinicensis, Ipomoea aquatica, I. coptica, Merremia hirta, Operculina petaloidea, and O. turpethum are predominantly recorded in wetland environments, including ponds, lakes, and riverbanks.

These findings highlight the broad ecological spectrum occupied by Convolvulaceae species in Udon Thani Province, demonstrating their ability to establish in diverse habitats ranging from dry grasslands to aquatic ecosystems.

3.3. Species Richness Distribution of Convolvulaceae Family from Udon Province

The Convolvulaceae family in Udon Thani Province is widely distributed, likely spanning all districts (Table 1, Figure 5). Nineteen species from seven genera—Argyreia capitiformis, A. mollis, A. nervosa, Camonea umbellata, Distimake vitifolius, Evolvulus nummularius, Ipomoea alba, I. aquatica, I. batatas, I. cairica, I. carnea, I. nil, I. obscura, I. pes-tigridis, I. purpurea, I. quamoclit, I. triloba, Merremia hederacea, and Porana volubilis—were recorded across all districts. Among them, Ban Phue District exhibits the highest species diversity.

3.4. Ecology of Convolvulaceae Family from Udon Thani Province

The ecology of all the species in this study is reported in Table 1. The family was found in five ecosystem types: deciduous dipterocarp forest, mixed deciduous forest, aquatic area, open area along the roadsides, and cultivated (Table 1). Eleven genera and 34 species, including Argyreia breviscapa, A. capitiformis, A. collinsiae, A. lanceolata, A. laotica, A. leucantha, A. mollis, A. osyrensis, A. splendens, Camonea bambusetorum, C. kingii, C. umbellata, Decalobanthus mammosus, Distimake quinatus, D. vitifolius, Evolvulus alsinoides, Ipomoea campanulata, I. coptica, I. nil, I. obscura, I. pes-tigridis, I. pileata, I. quamoclit, I. sagittifolia, I. triloba, Jacquemontia paniculata, Lepistemon binectarifer, Merremia gemella, M. hederacea, M. hirta, M. thorelii, M. verruculosa, Rivea ornata, and Xenostegia tridentata, have been found in deciduous dipterocarp forest.

A total of 20 species within seven genera were found in mixed deciduous forests, including Argyreia capitiformis, A. kerrii, A. osyrensis, Camonea bambusetorum, Decalobanthus mammosus, Distimake vitifolius, Ipomoea campanulata, I. coptica, I. nil, I. obscura, I. pes-tigridis, I. pileata, I. quamoclit, I sagittifolia, I. triloba, Lepistemon binectarifer, Merremia gemella, M. hederacea, M. hirta, and M. thorelii.

A collection of 12 species found in aquatic habitats belonged to eight genera: Aniseia martinicensis, Decalobanthus mammosus, Distimake cissoides, Hewittia malabarica, Ipomoea aquatica, I. asarifolia, Jacquemontia paniculata, Merremia gemella, M. hederacea, M. hirta, Operculina petaloidea, and O. turpethum.

The open area and roadside environment encompasses eleven genera and 25 species, including Aniseia martinicensis, Camonea bambusetorum, C. umbellata, Decalobanthus mammosus, Distimake vitifolius, Evolvulus alsinoides, E. nummularius, Hewittia malabarica, Ipomoea asarifolia, I. cairica, I. holubii, I. nil, I. obscura, I. pes-tigridis, I. pileata, I. quamoclit, I. triloba, Jacquemontia paniculata, Lepistemon binectarifer, Merremia gemella, M. hederacea, M. hirta, M. thorelii, Operculina petaloidea, and O. turpethum.

A total of 12 species belonging to four genera were cultivated as ornamental plants in home gardens and public gardens within the research area, including Argyreia nervosa, A. osyrensis, A. splendens, Evolvulus glomeratus, E. nummularius, Ipomoea alba, I. batatas, I. cairica, I. carnea, I. purpurea, I. quamoclit, and Porana volubilis. Their cultivation was largely due to the distinctive morphological characteristics of these species, particularly their leaves and flowers.

3.5. Phenology of Convolvulaceae Family from Udon Thani Province

The phenology of the Convolvulaceae family in Udon Thani Province follows typical patterns observed in tropical regions. Most species, including members of genera such as Argyreia, Ipomoea, and Porana, tend to flower and fruit during the rainy season when moisture levels are high. Flowering typically begins around May or June and continues through the peak of the rainy season, with fruiting following soon after, extending into late October or November. Some species may exhibit year-round flowering and fruiting, particularly in areas with consistent moisture, while others show more pronounced seasonal peaks. For instance, annual species like Ipomoea nil tend to complete their life cycles within a single season, while perennial vines like Argyreia and Porana may show more extended reproductive phases, while some species flower during winter around late December until March (Figure 6).

3.6. Conservation Status of Convolvulaceae Family from Udon Thani Province

• Criteria for assessing the conservation status of Convolvulaceae within the research area: The examination of specimens entailed evaluating the conservation status of diverse Convolvulaceae species (refer to Table 1, Figure 7). A total of 29 species were designated as rare species, while 23 species were categorized as common species.
• Endemic species: as per POWO, Table 1 reveals that 39 plants from the Convolvulaceae family are classified as native species. Thirteen species are documented as introduced species. Two species, Argyreia kerrii and A. leucantha, are recognized as endemic species.
• Evaluation criteria for the conservation status of Convolvulaceae based on the IUCN database: 44 species are categorized as Not Evaluated (NE) and six species are classified as Least Concern (LC), including Aniseia martinicensis, Ipomoea alba, I. aquatica, I. cairica, I. coptica, and Operculina petaloidea. Meanwhile, two species, Argyreia splendens and Ipomoea batatas, are listed as Data Deficient (DD).

3.7. Informant Agreement Ratio (IAR)

The Informant Agreement Ratio (IAR) provides a valuable indication of the degree of consensus among informants regarding the use of species for treating various health conditions (

Table 2. Informant Agreement Ratio (IAR) of Convolvulaceae used as medicinal plants found in Udon Thani Province.

Medical Categories	Number of Use Report	Number of Species	IAR
Obstetrics, gynecology, and urinary system	34	7	0.82
Nourishment	82	14	0.84
Gastrointestinal system	76	14	0.83
Respiratory system	45	9	0.82
Integumentary system	108	19	0.83
Circulatory system	14	2	0.92
Central nervous system	10	2	0.89
Lymphatic system	13	3	0.83
Immune system	12	3	0.82
Antipyretic	49	10	0.81
Infectious disease	16	3	0.87

). The IAR values for different medical categories, alongside the number of species used for each condition, reveal varying levels of agreement.

The highest IAR value of 0.92 was observed for the circulatory system category, which had only two species (Argyreia collinsiae and Ipomoea cairica), suggesting a strong consensus among informants. Other categories such as infectious disease (three species, IAR = 0.87) and nourishment (14 species, IAR = 0.84) also demonstrated notable agreement. The gastrointestinal system (14 species, IAR = 0.83) and integumentary system (19 species, IAR = 0.83) reflected strong consensus, indicating that informants largely agreed on the use of plant species for these conditions (Table 1 and Table S2).

Moderate agreement was observed in categories such as the respiratory system (nine species, IAR = 0.82) and the obstetrics, gynecology, and urinary system (seven species, IAR = 0.82), where the IAR values suggest some variation in the informants’ reports. The lymphatic system (three species, IAR = 0.83) and immune system (three species, IAR = 0.82) categories displayed fairly strong agreement, further highlighting the consistency in the informants’ knowledge of these treatments.

Finally, the antipyretic category (10 species, IAR = 0.81) had the lowest IAR, though it still indicates a reasonable level of consensus among informants.

These findings underscore the reliability of traditional knowledge, with varying degrees of agreement across medical categories. The results support the value of traditional ecological knowledge in the selection of plant species for health treatments.

3.8. Fidelity Level (FL)

Forty plant species were recognized as medicinal plants in the Udon Thani Province (Table S2). Of these, 19 species had the highest FL value of 100, including Argyreia lanceolata, A. laotica, A. osyrensis, A. splendens, Camonea kingii, Evolvulus alsinoides, E. nummularius, Hewittia malabarica, Ipomoea aquatica, I. coptica, I. purpurata, I. sagittifolia, Merremia gemella, M. hirta, M. thorelii, M. verruculosa, Operculina petaloidea, Rivea ornata, and Xenostegia tridentata.

The species with the highest number of use reports is Ipomoea batatas, commonly known as sweet potato. It is widely utilized for a range of medicinal applications, with various parts of the plant being used for different health conditions. The parts of the plant with the highest percentage of Fidelity Level (FL) include the root (25.81%) and the climber (22.58%). The roots are mainly used to support the gastrointestinal system, while the climber is utilized for its antipyretic properties. The young leaves (16.13%) are consumed to support lactation, while the whole plant (12.90%) is boiled and used to treat infectious diseases. The leaves (9.68%) are typically used for the integumentary system, and the storage root (12.90%) is used to support the urinary system. Each part of the plant offers unique health benefits, making it a valuable plant in traditional medicine.

The species with the second highest number of use reports is Argyreia collinsiae, which is widely used to treat various health conditions, with its different parts providing a broad range of medicinal benefits. The fruit (31.82%) is boiled and consumed to support the circulatory system, while the flower (27.27%) is also boiled to drink for nourishment. The climber (18.18%) is used for the respiratory system, and the leaves (13.64%) are crushed for respiratory health as well. Additionally, the root (9.09%) is boiled to drink to provide nourishment.

Ipomoea asarifolia is similarly versatile in its medicinal uses, with the whole plant (34.78%) being boiled and consumed for the gastrointestinal system. The leaves (26.09%) are boiled to support the integumentary system, while another portion of the leaves (8.70%) is used to boost the immune system. The climber (13.04%) is also used for the integumentary system, and the root (17.39%) is boiled to drink for the urinary system. Both plants have significant medicinal value, with different parts targeting a variety of bodily systems. For other plant species, fewer than five disease symptom categories were reported, as indicated in Table S2.

3.9. Cultural Importance Index (CI)

The use of Convolvulaceae in Udon Thani Province was classified into five categories (Table 1, Figure 8), with details on the Cultural Importance Index (CI) provided for each category as follows.

3.9.1. Convolvulaceae Used as Food

Four species are used as food including Ipomoea alba, I. aquatica, I. asarifolia, I. batatas, and I. cairica (

Table 3. Convolvulaceae in Udon Thani Province used as food.

Species	Used Parts	Preparation	Culinary Use
Ipomoea alba L.	Inflorescence	Boil until cooked or stir-fry until cooked	Used as a vegetable in savory dishes, often incorporated in stir-fries, soups, or curries
Ipomoea aquatica Forssk.	Leaves and stems	Eat fresh or boil until cooked	Eat fresh or boil until cooked to eat with Som tam (papaya salad) or chili dip, or cook in noodles, a main ingredient in water spinach curry, or stir-fry with oyster sauce
Ipomoea asarifolia (Desr.) Roem. & Schult.	Leaves and stems	Boil until cooked	Eat fresh or boil until cooked to eat with Som tam (papaya salad) or chili dip, or cook in noodles, a main ingredient in water spinach curry, or stir-fry with oyster sauce
Ipomoea batatas (L.) Lam.	Tubers	Boiled, baked, roasted, or fried	Boil until cooked or fry to eat as a snack, or mix with flour to make desserts and cook

).

The Cultural Importance (CI) values for the Ipomoea species, as food sources, varied significantly, reflecting their diverse roles in local diets and cultures. Among the species studied, I. batatas had the highest CI value of 1.93, indicating its significant cultural importance as a food source. Other species with notable CI values included I. alba (CI = 1.35), and I. asarifolia (CI = 1.35), which are also utilized in culinary practices.

In contrast, Ipomoea aquatica, with the lowest CI value of 0.85, is recognized for its nutritional value but appears to have a relatively lesser cultural significance as a food source compared to the other species. The variation in CI values reflects the varying degrees of cultural reliance on these species for food. Species with higher CI values, such as Ipomoea batatas, may be more integral to local diets, while others, like I. aquatica, may play a more supplementary or seasonal role.

The distribution of usage across different plant parts highlights the importance of the leaves (33.33%) and stems (33.33%) as the most commonly consumed portions, while storage roots (16.67%) are secondary in terms of utilization. Inflorescences also contribute 16.67%, though their use is more limited. The varying CI values across species indicate differing levels of reliance on these plants for sustenance, with some species playing a more vital role in the diet and culture of certain communities, particularly where leaves and stems are the central food sources (Figure 9).

3.9.2. Convolvulaceae Used as Animal Fodder

The Cultural Importance (CI) values for the species used as animal fodder vary significantly, reflecting the extent of their role in livestock nutrition and management within various cultural practices. Among the species examined, Ipomoea batatas exhibited the highest CI value of 1.93, indicating its significant use as animal fodder. Other species with high CI values include I. obscura (CI = 1.45), I. alba (CI = 1.35), and I. carnea (CI = 0.83), all of which are used for feeding livestock in certain regions.

Species with moderate CI values, such as Ipomoea pes-tigridis (CI = 0.95) and I. pileata (CI = 0.95), are also commonly used as animal fodder but may not play as central a role as those with higher CI values. These plants are utilized in various parts of the world, particularly for grazing animals or as supplementary fodder.

In contrast, species such as Ipomoea holubii (CI = 0.35) and I. triloba (CI = 0.18) have relatively low CI values, suggesting that they are less commonly used as animal fodder. While these species may still be fed to animals in specific regions, their cultural importance for animal nutrition is limited compared to other species in the Ipomoea genus.

Among the related species, Camonea umbellata and C. kingii, with CI values of 1.03, are also utilized as animal fodder, though their importance may be region-specific. Other species such as Decalobanthus mammosus (CI = 0.38) and Distimake quinatus (CI = 0.38) show limited use in animal fodder, reflecting their relatively minor role in livestock diets.

The varying CI values across these species highlight the differences in the cultural and practical reliance on these plants as animal fodder. Species with higher CI values are more widely recognized for their nutritional value in livestock diets, while those with lower CI values may be used in more localized or specific contexts, or may serve as supplementary feed.

3.9.3. Convolvulaceae Used as Ornamental Purposes

All the plants examined in this study are used entirely for ornamental purposes, with 100% of the entire plant being utilized (Figure 9) in gardens, landscaping, and decorative plantings. The Cultural Importance (CI) values of these species vary, reflecting their significance in ornamental horticulture across different regions and cultures.

Among the species with the highest CI values, Ipomoea obscura (CI = 1.45) and I. alba (CI = 1.35) are particularly valued for their aesthetic appeal, often used for ornamental purposes due to their striking flowers and attractive growth habits. Similarly, Evolvulus nummularius (CI = 1.18) is highly regarded for its ornamental qualities in landscaping.

Other species with notable CI values include Ipomoea pes-tigridis L. (CI = 0.95) and I. pileata (CI = 0.95), which are used in ornamental settings, though they are not as highly ranked as the top species. Additionally, species such as Argyreia collinsiae (Craib) Na Songkhla & Traiperm (CI = 1.03) and Camonea umbellata (CI = 1.03) are also valued for their aesthetic contributions to ornamental plantings.

Species with lower CI values, like Argyreia laotica (CI = 0.70), A. leucantha (CI = 0.55), and Merremia gemella (CI = 0.70), are still utilized for their ornamental value, though they may be less commonly used in large-scale ornamental designs. Jacquemontia paniculata (CI = 0.35) and Xenostegia tridentata (CI = 0.60), with their lower CI values, are more likely to be found in specialized or localized ornamental settings.

The varying CI values across these species reflect the differing levels of importance in ornamental horticulture. Plants with higher CI values are more commonly utilized for decorative purposes, while those with lower CI values may be used in more niche or specific ornamental contexts. Regardless of their CI values, all species in this study contribute to the beauty and diversity of ornamental landscapes, with the whole plant being used in their cultivation.

3.9.4. Convolvulaceae Used as Medicinal Plants

All the plants in this study are utilized in their entirety for medicinal purposes, with 100% of the plants being employed in traditional healing practices. The Cultural Importance (CI) values of these species reflect their varying degrees of significance in medicinal applications, with some plants being highly valued for their therapeutic properties (Table S2).

Among the species with the highest CI values, Ipomoea batatas stands out with a CI value of 1.93, followed by I. alba (CI = 1.35) and I. obscura (CI = 1.45), which are widely recognized for their medicinal uses, employing the whole plant for a variety of purposes.

Other species, such as Evolvulus nummularius (CI = 1.18) and Camonea umbellata (CI = 1.03), also have moderate to high cultural importance in traditional medicine, where they are used to treat a range of conditions. Argyreia breviscapa (CI = 0.73) and Ipomoea carnea (CI = 0.83) are also commonly employed for their medicinal benefits, though they are somewhat less significant compared to the highest-ranked species.

Species with lower CI values, such as Hewittia malabarica (CI = 0.50) and Xenostegia tridentata (CI = 0.60), may be used in more localized or niche medicinal practices. Despite their lower CI values, they still contribute to traditional healing systems, often in specific regions or for particular ailments.

Overall, the varying CI values reflect the diverse roles these plants play in traditional medicine. Plants with higher CI values are central to medicinal practices, while those with lower CI values have more specialized uses. Regardless of their CI ranking, all species in this study are valued for their medicinal properties, with 100% of the plant being utilized in healing practices.

The analysis of plant part usage revealed that the majority of the plant is utilized in its entirety or for specific structures, with leaves accounting for 27.78% and whole plants comprising 28.89% of the total usage. Storage roots or roots followed closely with 18.89%, while stems contributed 12.22%. Fruits and seeds were used in 8.89%, and inflorescences had the least representation at 3.33%. These results indicate that the primary plant parts used are leaves and whole plants, with other parts like fruits, seeds, and inflorescences playing a lesser role (Figure 9).

3.9.5. Convolvulaceae Used as Horticultural Cultivation

All the plants in this study are fully utilized in horticultural cultivation, with 100% of the entire plant being employed for various horticultural purposes. The Cultural Importance (CI) values of these species vary, reflecting their significance in horticultural cultivation.

Among the species with the highest CI values, Ipomoea batatas (CI = 1.93) stands out, followed by I. alba (CI = 1.35) and I. asarifolia (CI = 1.35), which are cultivated widely for their horticultural value. These species play an important role in traditional farming systems, contributing to soil health, fodder production, and other horticultural practices.

Other species with moderate to high horticultural value include Evolvulus nummularius (CI = 1.18), Ipomoea cairica (CI = 1.18), and Operculina turpethum (CI = 1.18), which are also cultivated for their horticultural benefits, such as for use as cover crops, fodder, or for their utility in crop rotation systems.

Species with lower CI values, such as Argyreia nervosa (CI = 0.93) and A. osyrensis (CI = 0.80), are also used in horticultural contexts, though they may have a more localized role in cultivation. Similarly, species like Evolvulus glomeratus (CI = 0.70) and Hewittia malabarica (CI = 0.50) contribute to horticultural systems in specific regions or under particular conditions.

The varying CI values among these species reflect their different levels of importance in horticultural cultivation. Plants with higher CI values are integral to horticultural systems, while those with lower CI values may serve more specialized or supplementary roles. Regardless of their CI ranking, all the species in this study contribute to horticulture, with the entire plant being utilized in farming practices.

The plants in this study are predominantly used in their entirety, with 66.67% of the plants being utilized as whole plants for trade. This highlights their significance in various markets, where the complete plant is often needed for ornamental, medicinal, or horticultural purposes.

Among the specific plant parts, the stems and leaves are each used in 13.33% of cases, indicating their important role in trade, particularly for medicinal or cultural applications. The inflorescences, though used less frequently, still account for 6.67% of the utilization. Interestingly, the storage roots are not utilized (0.00%), suggesting that the parts of the plants most commonly traded are the above-ground portions (Figure 9).

The plants in this study not only have cultural and horticultural importance, but they also contribute to the livelihoods of traders, with varying levels of economic impact. The average yearly income (in THB) generated by the sale or trade of these plants reflects their value in local markets and traditional economies (

Table 4. The economic value of the Convolvulaceae family from Udon Province.

No.	Scientific Name	Part of Trades	Price (THB/kg.)		Trading Periods (Months)	Average Yearly Income (THB/a Trader)
			Max	Min
1.	Argyreia nervosa (Burm.f.) Bojer	Whole plants	150	120	1–12	81,000
2.	Argyreia osyrensis (Roth) Choisy	Whole plants	50	20	1–12	46,200
3.	Argyreia splendens (Hornem.) Sweet	Whole plants	150	100	1–12	75,000
4.	Evolvulus glomeratus Nees & Mart.	Whole plants	100	65	1–12	79,200
5.	Evolvulus nummularius (L.) L.	Whole plants	20	10	1–12	54,000
6.	Hewittia malabarica (L.) Suresh	Whole plants	80	50	1–12	78,000
7.	Ipomoea alba L.	Inflorescence	120	100	1–12	79,200
8.	Ipomoea aquatica Forssk.	Leaves, stem	24	20	1–12	60,720
9.	Ipomoea asarifolia (Desr.) Roem. & Schult.	Whole plants	50	40	1–12	67,500
10.	Ipomoea batatas (L.) Lam.	Storage root	18	15	1–12	59,400
11.	Ipomoea cairica (L.) Sweet	Whole plants	50	35	1–12	66,300
12.	Ipomoea quamoclit L.	Whole plants	100	50	1–12	85,500

).

Among the species with the highest economic returns, Ipomoea quamoclit (THB 85,500) stands out as the most profitable, followed by Ipomoea alba and Evolvulus glomeratus (both with THB 79,200), which generate substantial income for traders. These plants are likely in high demand due to their utility in ornamental, medicinal, or horticultural markets, leading to higher yearly earnings.

Other species that contribute to traders’ incomes include Ipomoea asarifolia (THB 67,500), I. cairica (THB 66,300), and Argyreia splendens (THB 75,000), indicating a steady income stream for those involved in their trade. Additionally, Argyreia nervosa (THB 81,000) and Hewittia malabarica (THB 78,000) also offer moderate economic returns, underscoring their role in local economies.

Species with relatively lower income figures, such as Argyreia osyrensis (THB 46,200) and Evolvulus nummularius (THB 54,000), still contribute to the livelihood of traders but may be less commercially sought after compared to those with higher economic returns.

These varying income levels reflect not only the demand for the plants in specific markets but also their availability, utility, and role in local economies. Traders dealing in species with higher income values may benefit from broader markets or specialized niches, while those trading in species with lower income values may serve more localized or niche demands. Regardless of income levels, all the species in this study play a significant role in supporting the economic well-being of traders.

4. Discussion

The investigation of the diversity of the Convolvulaceae family in Udon Thani Province reveals a remarkable variety of species within this plant family, emphasizing the richness of the region’s flora. With 15 genera and 52 species identified, the most diverse genus, Ipomoea, reflects the family’s ecological adaptability, found in both aquatic and terrestrial environments. The dominance of Ipomoea (17 species) and Argyreia (12 species) is consistent with previous studies that suggest these genera thrive in tropical and subtropical climates [28]. Ipomoea aquatica, for example, is well known for its rapid growth and dual purpose as an ornamental and edible plant [29]. The presence of other genera such as Merremia, Evolvulus, and Operculina highlights the family’s flexibility in adapting to various ecological niches, ranging from wetlands to disturbed habitats.

The relatively low diversity within genera like Aniseia, Hewittia, and Jacquemontia, with only one species recorded per genus, contrasts sharply with the abundance of Ipomoea and Argyreia. These smaller genera still play vital roles in the ecosystem, contributing to the ecological balance of their habitats through their climbing or twining growth habits, which provide ground cover and shelter for various organisms [30]. The ornamental potential of species like Argyreia nervosa and Operculina turpethum further underscores the economic importance of these plants, which are valued not only for their aesthetic qualities but also for their medicinal properties [31]. This study provides significant novel data that highlight the understanding of the Convolvulaceae family in Udon Thani, highlighting its untapped potential for sustainable development in horticulture and medicine.

Aniseia Choisy is a small genus of Convolvulaceae that is commonly recognized for its twining or climbing growth habit. Species in this genus are characterized by their funnel-shaped flowers and simple, undivided leaves. The plants are predominantly herbaceous. Globally, the genus is represented by only a few species, with Aniseia martinicensis (Jacq.) Choisy being the most widely recognized. In this study, A. martinicensis is the only species of the genus identified. It is an herbaceous vine, typically found as an aquatic or semi-aquatic plant.

Argyreia Lour. is a genus primarily consisting of woody climbers and shrubs, and is known for its large, often heart-shaped leaves, vibrant funnel-shaped flowers, and robust climbing vines. It holds significant economic potential as an ornamental plant and in horticulture due to its aesthetic appeal, medicinal properties, and adaptability. In the Udon Thani Province study, Argyreia was the second most diverse genus, with 11 species recorded (Table 1), namely Argyreia breviscapa (Kerr) Ooststr., A. capitiformis (Poir.) Ooststr., A. collinsiae (Craib) Na Songkhla & Traiperm, A. kerrii Craib, A. lanceolata Choisy, A. laotica Gagnep., A. leucantha Traiperm & Staples, A. mollis (Burm.f.) Choisy, A. nervosa (Burm.f.) Bojer, A. osyrensis (Roth) Choisy, and A. splendens (Hornem.) Sweet. Some notable species of Argyreia include A. nervosa (also known as Bai Ra Bat in Thai vernacular), which is known for its psychoactive properties and prized for its large, showy, trumpet-shaped flowers in shades of purple, pink, or white. These plants are excellent choices for trellises, pergolas, and fences due to their vigorous climbing habit. Moreover, Argyreia lanceolata, A. laotica, A. leucantha, A. mollis, and A. splendens are recognized for their gigantic, showy flowers. The leaves of all species in this genus are attractive, large, heart-shaped leaves that add lush greenery to gardens, making them popular in landscape design. Their capacity for rapid coverage of structures renders them optimal for the construction of green walls, improving urban aesthetics, and fostering sustainable architecture. Therefore, Argyreia possesses significant potential in the economic and horticultural domains. Its function as an ornamental species, along with its medicinal properties, establishes it as a significant genus for sustainable development.

Camonea Raf. is a genus comprising twining vines typically. Plants in this genus are often distinguished by their slender, twining stems, simple leaves, and brightly colored, funnel-shaped flowers. In the investigation conducted in Udon Thani Province, Camonea was represented by three species: C. bambusetorum (Kerr) A.R.Simões & Staples, C. kingii (Prain) A.R.Simões & Staples, and C. umbellata (L.) A.R.Simões & Staples, rendering it one of the more diverse genera in the region, following Ipomoea, Argyreia, and Merremia. Camonea and Merremia are both placed within the tribe Merremieae in the Convolvulaceae family. Camonea and Merremia are closely related but distinct lineages. In some classifications, species originally placed in Merremia have been moved to Camonea based on genetic data. They share similar floral structures, such as funnel-shaped flowers with radial symmetry, and often have white or yellow flowers. Their fruits are typically capsules with dehiscent seeds, similar to other genera in the family. Camonea is distinguished by more specific traits like flower morphology, especially in calyx and corolla structure, and the arrangement of stamens, while Merremia includes a broader diversity of species with some variation in leaf shape, floral size, and growth habit. All species within the genus often have beautifully colored flowers (yellow, yellowish, or white), and lush and green leaves, making them attractive for incorporation in gardens, landscapes, and as ornamental plants.

Decalobanthus Ooststr. is a genus consisting of twining or climbing vines. The genus is characterized by its large, heart-shaped leaves and conspicuous, funnel-shaped flowers. Its name reflects the distinctive 10-lobed (deca-lobate) structure of its floral parts in some species, though not all members exhibit this trait. In the Udon Thani Province study, only one species of Decalobanthus was recorded. One well-known species, Decalobanthus mammosus (Lour.) A.R.Simões & Staples (formerly Merremia mammosa), is recognized for its rapid growth and ability to cover large areas, which can sometimes make it invasive outside its native range.

Distimake Raf. is a genus consisting of twining vines. It was previously classified under the genus Ipomoea, but molecular studies have led to its reclassification as a separate genus. Distimake species are characterized by their climbing habit, simple leaves, and funnel-shaped flowers, which often resemble those of other genera in the family. In the investigation conducted in Udon Thani Province, three species of Distimake were recorded, including D. cissoides (Lam.) A.R.Simões & Staples, D. quinatus (R.Br.) A.R.Simões & Staples, and D. vitifolius (Burm.f.) Pisuttimarn & Petrongari. This highlights its modest representation in the region compared to more diverse genera like Ipomoea and Argyreia. Some species of Distimake are valued for their ornamental appeal, while others may have ecological roles as cover plants in natural habitats.

Evolvulus L. is a genus of herbaceous plants and small shrubs. Unlike many other members of the family that are twining vines, Evolvulus species are typically non-climbing and more compact in growth habit. Evolvulus species are distinguished by their small, often silvery or hairy leaves, and their delicate, funnel-shaped flowers, which are usually blue, white, or lavender. These flowers are smaller compared to those of genera like Ipomoea, but they still attract pollinators such as bees and butterflies. In the Udon Thani Province study, Evolvulus was represented by three species, including E. alsinoides (L.) L., E. glomeratus Nees & Mart., and E. nummularius (L.) L., making it moderately diverse compared to other genera in the region. One of the most well-known species is E. alsinoides, which has traditional medicinal uses, particularly in Ayurvedic medicine, and is believed to have cognitive and anti-inflammatory properties. Evolvulus species are also appreciated for their ornamental value, especially in rock gardens or as ground cover.

Hewittia Wight & Arn. is a small genus comprising herbaceous twining or climbing plants. The genus is relatively less diverse compared to others in the family and is characterized by its twining stems, heart-shaped or ovate leaves, and funnel-shaped flowers that are often pale yellow or white with darker centers. These plants are typically found growing along roadsides, in disturbed habitats, or in moist environments such as riverbanks and wetlands. Hewittia species are notable for their ability to rapidly colonize open or disturbed areas due to their twining nature. In the investigation of Convolvulaceae in Udon Thani Province, only one species of Hewittia (H. malabarica (L.) Suresh) was recorded, reflecting its limited diversity in the region. Its seeds, leaves, and roots have been reported to have various therapeutic properties, such as treating stomach issues and wounds.

Ipomoea L. is a highly diverse genus of plants known as morning glories. In the investigation of Convolvulaceae in Udon Thani Province, Ipomoea was noted as the most diverse genus with 17 species identified, including I. alba L., I. aquatica Forssk., I. asarifolia (Desr.) Roem. & Schult., I. batatas (L.) Lam., I. cairica (L.) Sweet, I. carnea Jacq., I. campanulata L., I. coptica (L.) Roth, I. holubii Baker, I. nil (L.) Roth, I. obscura (L.) Ker Gawl., I. pes-tigridis L., I. pileata Roxb., I. purpurata (L.) Roth, I. quamoclit L., I sagittifolia Burm.f., and I. triloba L. This diversity underscores its ecological importance and adaptability in the region. Notable species include Ipomoea aquatica, generally referred to as morning glory or Pak Bung, which is a rapidly growing aquatic or semi-aquatic plant, recognized for its consumable branches and foliage; it also has significant horticultural potential beyond its edible purposes. Ipomoea batatas or sweet potato is primarily cultivated for its edible tubers, but it also has significant horticultural potential. Sweet potatoes provide both ornamental value and nutritional benefits, rendering them ideal for use in edible landscaping schemes. Ipomoea purpurea, known as the common morning glory, is a rapidly growing and twining annual vine, popular for its distinctive trumpet-shaped blossoms (purple color), that is often planted for ornamental purposes. And Ipomoea carnea, referred to as bush morning glory or pink morning glory, is a rapidly growing perennial shrub, popular for its distinctive trumpet-shaped blossoms (pink color), that is also planted for ornamental purposes.

Jacquemontia Choisy is a genus consisting of twining vines and small shrubs. Plants in this genus are typically characterized by their delicate, twining stems, small, simple leaves, and attractive, often small, funnel- or bell-shaped flowers, usually blue, white, or purple. In this study, only one species was recorded, J. paniculata (Burm.f.) Hallier f., indicating its limited presence in the region.

Lepistemon Blume is a genus of plants generally characterized by their twining or climbing habit, with leaves and flowers typical of the family. In this study, Lepistemon binectarifer (Wall.) Kuntze is the only species identified.

Merremia Dennst. is another significant genus within the Convolvulaceae family, known for its twining vines and beautiful flowers. The flowers are large, showy, and funnel- or bell-shaped. They usually have five petals that are fused into a corolla. The color of the flowers varies widely, usually white, yellow, or pink. The flowers are usually solitary or in small clusters. In this study, Merremia was identified as the third most diverse genus, comprising five species: M. gemella (Burm.f.) Hallier f., M. hederacea (Burm.f.) Hallier f., M. hirta (L.) Merr., M. thorelii (Gagnep.) Staples, and M. verruculosa S.Y.Liu, demonstrating its adaptability and ecological significance in the area. All Merremia species in this study produce attractive trumpet-shaped flowers in vibrant colors such as yellow, white, and purple, making them ideal for ornamental use in gardens, trellises, and fences.

Operculina Silva is a genus typically consisting of climbing or trailing vines with a vigorous twining habit. The leaves are simple, large, and either heart-shaped or ovate, arranged alternately along the stems. Depending on environmental conditions, some species may exhibit lobed or slightly divided leaves. The flowers, one of the genus’s most striking features, are large, funnel-shaped, and commonly white or pale yellow. They consist of five fused petals forming a broad, bell-like corolla and are typically solitary or found in small clusters at the leaf axils. The genus name Operculina refers to the “lid-like” (operculate) structure that sometimes covers the fruit capsule. In Udon Thani Province, this genus is represented by two species: O. petaloidea (Choisy) Ooststr. and O. turpethum (L.) Silva Manso. Both species feature large, funnel-shaped flowers in shades of white, cream, or yellow, making them striking additions to gardens.

Porana Burm.f. is a genus known for its ornamental value; it features dense clusters of white flowers and a twining growth habit, making it a notable part of the local flora during its flowering season. In Udon Thani Province, Porana volubilis Burm.f. is the only species in this genus.

Rivea Choisy is a genus known for its climbing habit and ornamental flowers, making it a significant species in both natural and cultivated landscapes. The flowers are funnel-shaped with a broad, open corolla, and the fused petals form a tubular structure, which is typical of the family. They are usually white or pale in color, often fragrant, and bloom in clusters. In Udon Thani Province, Rivea ornata (Roxb.) Choisy is the only species present.

Xenostegia D.F.Austin & Staples is a genus represented in Udon Thani Province by a single species, Xenostegia tridentata (L.) D.F. Austin & Staples, a climbing herbaceous plant. The specific epithet “tridentata” refers to the tooth-like lobes at the base of the leaves; typically, the plant features three lobes on each side. The plant’s modest flowers and climbing habit make it a notable element of the local flora, particularly in areas with open or disturbed vegetation. The smooth edges of its leaves further enhance its delicate appearance.

The findings of this study provide valuable insights into the diversity and ecological roles of the Convolvulaceae family in Udon Thani Province. This region, with its varied species, serves as an important site for further research into the potential uses of these plants in both ornamental and practical applications. The unique distribution of species within the family and their diverse habitats suggest that Udon Thani’s Convolvulaceae flora could be a promising resource for both ecological conservation and the development of new horticultural practices. Future studies may explore the genetic relationships among these species, especially within genera like Camonea and Merremia, to better understand their evolutionary adaptations and potential for future cultivation.

The Convolvulaceae family in Udon Thani Province displays remarkable growth from diversity, enabling species to thrive across various habitats. Herbaceous vines, particularly Ipomoea species, dominate disturbed areas like roadsides and wetlands due to their rapid twining and spreading abilities. Similarly, woody vines such as Argyreia, Porana, and Rivea are well adapted to forested habitats, climbing trees and shrubs to access sunlight, contributing to vertical habitat complexity and forest regeneration [32].

Shrub-like species, including Ipomoea carnea and Argyreia mollis, combine upright growth with structural resilience, enabling adaptation to diverse environments. Prostrate herbs such as Evolvulus spp. thrive in open areas, stabilizing soils and supporting nutrient cycling. Aquatic and semi-aquatic species like Ipomoea aquatica and Merremia hirta further highlight the family’s versatility, playing vital roles in wetland ecosystems, including erosion control and habitat provision [33].

This ecological flexibility underscores the importance of Convolvulaceae in habitat restoration and ecosystem management. Future studies should explore their specific ecological roles and adaptive strategies to better understand their contributions to ecosystem resilience and biodiversity conservation.

The Convolvulaceae family in Udon Thani Province is widely distributed, with 16 species across six genera recorded throughout the region. Most species were observed in multiple districts, while Argyreia lanceolata was uniquely found in Ban Phue, suggesting localized habitat preferences. High species diversity in districts such as Ban Phue, Ban Dung, Kumphawapi, Mueang, and Na Yung underscores their significance for Convolvulaceae biodiversity. This diversity is likely due to the varied ecological conditions, including wetlands, forests, and grasslands, which support a wide range of species. Differences in elevation, microclimates, and water availability further create distinct habitats, fostering species adaptation and specialization.

The adaptability of genera like Ipomoea and Merremia to diverse environments, including wetlands and disturbed habitats, underscores their ecological versatility [34]. The localized presence of Argyreia lanceolata suggests specific microhabitat requirements, warranting further study. Protecting species-rich areas and exploring environmental factors influencing species distribution are crucial for biodiversity conservation and habitat management.

The similarities in species diversity among Convolvulaceae plants across five different ecological types in Udon Thani Province were analyzed using UPGMA and are presented in a dendrogram (Figure 10). These ecological types include aquatic areas, deciduous dipterocarp forest (DDF), mixed deciduous forest (MDF), open areas and roadsides, and cultivated lands. Clustering was conducted using the Jaccard Similarity Index and analyzed with the UPGMA method. The high cophenetic correlation coefficient of 0.9466 supports the reliability of the clustering, indicating that the results accurately reflect the relationships between species in these habitats.

The aquatic areas and DDF show the highest similarity in species diversity, forming the closest cluster in the dendrogram. This strong connection can likely be explained by overlapping environmental conditions, such as seasonal water availability and comparable vegetation structures. Species adapted to periodic moisture are common in both settings, leading to significant overlap in species composition. These habitats may function as ecological buffers, supporting species that thrive under similar climatic and soil conditions.

The MDF exhibits a moderate similarity to the aquatic and DDF clusters, reflecting some shared species due to transitional ecological features. This forest type acts as a bridge, blending traits of both deciduous and aquatic environments. Species capable of tolerating variable levels of moisture and canopy cover are often found in these zones. However, MDF also has distinct ecological characteristics, such as increased competition for resources and specific soil properties, which contribute to its unique diversity.

Open areas and roadsides form a separate cluster that shows moderate similarity to forested habitats but diverges notably due to human influence. Activities such as road construction and land clearing create disturbed environments that favor resilient, fast-growing Convolvulaceae species. These areas are dominated by plants that can adapt to high levels of sunlight, compacted soils, and frequent disturbances, emphasizing the impact of human-modified environments on plant diversity.

Cultivated areas form the most distinct cluster, differing substantially from the natural habitats. This divergence is primarily due to the intentional selection of species in cultivation, often for aesthetic or economic purposes. As a result, cultivated areas typically have reduced species diversity, focusing on a limited number of plants with specific characteristics. The separation highlights how horticultural and horticultural practices alter natural ecosystems.

Interestingly, cultivated areas still show some similarity to aquatic habitats in species diversity. This connection arises from the conditions created in cultivation, such as irrigation systems that replicate wetland environments. Species like Ipomoea aquatica, which thrive in moist conditions, are often selected for cultivation due to their ornamental and horticultural value. These species bridge the gap between natural aquatic habitats and managed environments.

Aquatic habitats, with their wet and humid conditions, naturally support species adapted to creeping growth forms, waterlogged soils, and fluctuating environments. These traits also make such plants suitable for cultivated settings. In contrast, species from DDF and MDF tend to have stricter ecological requirements and are less suited to managed environments. This adaptability of aquatic species strengthens their association with cultivated areas.

The findings emphasize the importance of conserving natural habitats, as each contributes uniquely to the overall diversity of Convolvulaceae in Udon Thani Province. Aquatic areas, DDF, MDF, and roadside habitats each play a critical role in maintaining biodiversity. At the same time, encouraging sustainable and diverse cultivation practices can help reduce the ecological gap between natural and managed ecosystems. By preserving genetic and species diversity, these efforts can support ecological balance and contribute to long-term biodiversity management in the region.

The phenology of Convolvulaceae species in Udon Thani Province aligns with typical tropical patterns, with most species flowering and fruiting during the rainy season from May to November. The high moisture availability during this period supports reproductive activity, particularly in genera such as Ipomoea, Argyreia, and Porana. Annual species like Ipomoea nil complete their life cycles in a single season, while perennial vines like Argyreia and Porana exhibit more extended reproductive phases, reflecting their adaptability to both seasonal and consistent moisture conditions [33].

Certain species show year-round flowering and fruiting in areas with stable water availability, indicating the family’s ecological flexibility. This seasonal phenology is crucial for pollinators and seed dispersers, contributing to ecosystem dynamics. Future studies could explore the impact of climate variability on reproductive cycles, providing insight into how environmental changes may influence these patterns [35].

The conservation status of Convolvulaceae species in Udon Thani Province, as assessed using the IUCN Red List [23], offers important insights into the current state of these plants and the conservation challenges they face. A significant issue is the lack of IUCN classifications for many species, highlighting the need for further research and focused conservation efforts. Several species, including Argyreia splendens and Ipomoea batatas, are classified as Data Deficient, indicating insufficient information to evaluate their extinction risk. Meanwhile, six species are listed as Least Concern, suggesting stable populations but still requiring ongoing monitoring to ensure their continued survival. Additionally, the identification of two endemic species calls for heightened conservation attention. The conservation outlook for Convolvulaceae species in Udon Thani Province is a mix of stability and concern. While some species show relatively low extinction risk, many others remain under-studied or are at risk due to habitat loss and other factors. To safeguard these species, it is crucial to prioritize research, regular monitoring, and targeted conservation actions, especially for those with Data Deficient or Vulnerable statuses. Without adequate conservation efforts, some species may face significant declines, potentially leading to the loss of biodiversity in the region.

The Informant Agreement Ratio (IAR) analysis for Convolvulaceae species used in Udon Thani Province reveals varying levels of consensus among informants across different health conditions. Strong agreement was found in categories such as the circulatory system (IAR = 0.92) and infectious diseases (IAR = 0.87), indicating a shared understanding of specific plant species for these treatments. Other categories like nourishment (IAR = 0.84) and gastrointestinal (IAR = 0.83) also showed notable consensus, supporting the reliability of traditional knowledge in these medical areas. These results are consistent with other studies that highlight the strength of traditional ecological knowledge, particularly when plant species are commonly used for well-established treatments [35,36,37,38].

Moderate agreement was observed in categories like the respiratory system (IAR = 0.82) and the obstetrics, gynecology, and urinary System (IAR = 0.82), suggesting some variability in informants’ plant choices for these conditions. The lower IAR of 0.81 in the antipyretic category further reflects the diversity of plant species used for fever treatment, possibly due to a wider range of options available. These findings emphasize the value of traditional ecological knowledge, with the need for continued research to document and preserve this knowledge for both health care and biodiversity conservation in Udon Thani Province.

The analysis of plant species with the highest frequency of local use in Udon Thani Province revealed that 19 species had a 100% Fidelity Level (FL), highlighting their widespread and crucial role in local medicinal practices. Among these, species like Argyreia lanceolata, Evolvulus alsinoides, and Ipomoea aquatica are commonly used for a variety of health conditions, demonstrating their importance in traditional medicine. Notably, Ipomoea batatas, or sweet potato, was recognized for its versatile medicinal uses, with different parts of the plant, such as the root and climber, showing significant percentages of Fidelity Level and being used for a range of therapeutic applications including gastrointestinal support and antipyretic purposes. This is consistent with other ethnobotanical studies that emphasize the multifunctional roles of certain plants in traditional healthcare systems [39,40].

Similarly, Argyreia collinsiae and Ipomoea asarifolia demonstrated a wide variety of uses across multiple body systems, with different parts of the plants being used for treatments related to the circulatory, gastrointestinal, integumentary, and immune systems. The broad usage of these species underscores the local community’s reliance on specific plants to address diverse health conditions, which is a finding that aligns with previous research on the rich medicinal potential of plants in traditional healing systems [41,42]. While other species had fewer reported uses, the diversity of applications for the high-FL plants reflects the depth of traditional ecological knowledge present in Udon Thani. These findings underscore the importance of conserving such plants, as they play a vital role in the healthcare system and biodiversity preservation.

The varying Cultural Importance (CI) values of Ipomoea species highlight their diverse roles as food sources within local communities. I. batatas exhibited the highest CI value of 1.93, reflecting its significant use as a food source, particularly for its edible tubers and leaves. In contrast, I. aquatica, with the lowest CI value (0.85), is utilized for its nutritional value but holds a relatively lesser cultural significance in the diet. Other species, such as I. obscura (CI = 1.45) and I. alba (CI = 1.35), are also consumed for their edible parts, but their cultural importance as food sources is more limited compared to I. batatas.

The results also indicate that the leaves and stems are the most commonly consumed parts of these plants, making up 33.33% of usage each, while storage roots and inflorescences contribute 16.67% each. This suggests that species with higher CI values, such as Ipomoea batatas, may serve as staple foods, while others, like I. aquatica, are used more seasonally or as supplementary food sources. These findings reinforce the cultural and nutritional significance of Ipomoea species in local diets, as seen in similar studies [43,44,45].

The varying Cultural Importance (CI) values of Ipomoea species used as animal fodder highlight their differing roles in livestock nutrition across regions. I. batatas, with the highest CI value of 1.93, play a crucial role in livestock diets, suggesting their widespread use and nutritional significance in various cultural contexts. Other species, such as I. obscura (CI = 1.45) and I. alba (CI = 1.35), also serve as important feed sources but may be used less extensively compared to I. batatas. Species with moderate CI values like I. pes-tigridis L. (CI = 0.95) are utilized primarily for grazing or as supplementary fodder, reflecting their secondary role in livestock feeding [46,47].

In contrast, species such as Ipomoea holubii (CI = 0.35) and I. triloba (CI = 0.18) are less commonly used, with limited cultural importance in animal nutrition. The overall use of these plants as complete feed sources emphasizes their full utility in livestock management, with certain species being more vital in particular regions due to their nutritional value or availability. These findings suggest that species with higher CI values are integral to broader livestock feeding systems, while those with lower values tend to have more localized or supplementary roles [19].

The Cultural Importance (CI) values of the Convolvulaceae species used for ornamental purposes vary, reflecting their differing roles in decorative horticulture across regions. Species like Ipomoea obscura (CI = 1.45) and I. alba (CI = 1.35) are highly valued for their aesthetic appeal, with their striking flowers making them common choices for gardens and landscaping [15]. Evolvulus nummularius (CI = 1.18) is similarly prized for its attractive qualities in ornamental settings. Meanwhile, species such as I. pes-tigridis (CI = 0.95) and I. pileata (CI = 0.95) have moderate CI values, indicating their use in ornamental plantings but on a smaller scale compared to the more highly valued species.

Plants with lower CI values, including Argyreia laotica (CI = 0.70) and Merremia gemella (CI = 0.70), are less commonly used in large-scale ornamental designs, yet still play a role in specialized or localized horticultural applications. Despite the varying CI values, all the species in this study contribute to the aesthetic richness and diversity of ornamental landscapes, with the entire plant being used in landscaping and decorative plantings [48]. These findings highlight the varying levels of reliance on these plants in ornamental horticulture, with higher CI values indicating broader usage, while lower values suggest more niche applications.

The varying Cultural Importance (CI) values of Convolvulaceae species underscore their diverse roles in traditional medicine within local communities. Ipomoea batatas exhibited the highest CI value of 1.93, reflecting its significant use in treating various ailments throughout its entire plant. In contrast, Hewittia malabarica, with a lower CI value of 0.50, contributes to traditional healing practices in more specific or localized contexts. Other species, such as I. alba (CI = 1.35) and I. obscura (CI = 1.45), are also valued for their medicinal properties, though their significance is more moderate compared to I. batatas.

The analysis revealed that leaves and whole plants are the most frequently utilized parts, comprising 27.78% and 28.89% of usage, respectively, while roots (18.89%), stems (12.22%), and fruits or seeds (8.89%) play lesser roles. This pattern indicates that species with higher CI values, like Ipomoea batatas, are integral to traditional healing practices, while others with lower CI values, such as Xenostegia tridentata (CI = 0.60), are used for more specialized purposes. These findings highlight the cultural and therapeutic importance of Convolvulaceae species, emphasizing their crucial role in sustaining traditional medicinal knowledge [41,49].

The Convolvulaceae family plays a significant role in horticultural practices, with various species being cultivated for their multiple uses. These plants are fully utilized in farming, with each part of the plant serving different purposes. The Cultural Importance (CI) values of the species in this study indicate their varying roles in horticultural systems, ranging from high-value plants like Ipomoea batatas (CI = 1.93) to those with more localized horticultural roles such as Hewittia malabarica (CI = 0.50). Plants with higher CI values are integral to farming systems, contributing to soil health, crop rotation, and fodder production, while those with lower CI values often serve specialized or regional functions.

The utilization of entire plants in horticulture reflects their significance, with a majority being traded as whole plants. While some parts such as stems and leaves are also traded for medicinal or cultural uses, the inflorescences and roots are less commonly used. The varying parts of the plant are traded depending on their cultural, medicinal, or horticultural value, which supports local markets. The emphasis on whole plants highlights the comprehensive role these species play in both local economies and horticultural systems.

Economic values from these plants are diverse, with species like Ipomoea quamoclit generating substantial income for traders, reaching up to THB 85,500 annually. Conversely, species like Argyreia osyrensis offer lower returns, around THB 46,200. These variations in economic returns reflect not only the demand in specific markets but also the availability and utility of these plants in horticultural cultivation, medicine, and ornamentation. Despite differences in income, all these species contribute significantly to the livelihoods of traders, reinforcing their value in both economic and horticultural contexts.

This study underscores the cultural and horticultural significance of the Convolvulaceae species, highlighting their multifaceted uses in farming systems and their contribution to the economic well-being of local communities. The varying CI values, plant part utilization, and income generation further demonstrate the diverse roles these plants play, with some species being more central to horticultural practices and others serving specialized niches. The integration of these plants into both local economies and traditional farming practices emphasizes their essential role in sustainable horticulture [50,51].

The price data collected for the plants in this study also reveal significant insights into their economic value and potential for horticultural development. Plants with higher economic values are typically in greater demand, as reflected in their price fluctuations over the year. This trend suggests that such plants have high potential in horticulture, both as ornamental species and for other local uses. The price data indicate that plants with strong market demand can be cultivated more extensively to help balance supply and demand. This could benefit local farmers by improving their income opportunities while also ensuring a more sustainable supply of these species for the market.

Furthermore, the high economic value of these plants not only highlights their importance in local trade but also points to their potential for wider horticultural use. The balance between supply and demand could be achieved through strategic cultivation and promotion, ensuring that these species are not only preserved but also economically viable for long-term growth. Expanding cultivation efforts may also increase the diversity of plants available in the horticultural market, thus contributing to biodiversity conservation and enhancing the sustainability of local agricultural practices.

As such, it is essential to consider the economic implications of cultivating high-value plants. The cultivation of plants with high market value offers an opportunity to meet market needs, improve local livelihoods, and ensure that the plants continue to be available for future generations. Further studies on cultivation techniques, market trends, and sustainable practices will be crucial in realizing the full potential of these species in horticultural and economic development.

5. Conclusions

This study highlights the significance of the Convolvulaceae family in Udon Thani Province, Thailand, documenting 15 genera comprising 52 species. Ipomoea is the most diverse genus. The family was recorded in five distinct ecosystem types: deciduous dipterocarp forest (34 species), open areas and roadsides (24 species), mixed deciduous forest (20 species), aquatic habitats (12 species), and cultivated areas (12 species). A total of 52 species were recorded in this study. Of these, seven species (13.46%) were found exclusively in cultivation, while eight species (15.39%) were observed in both cultivation and natural habitats. The remaining 37 species (71.15%) were found only in their natural habitats and not in cultivation. Within the study area, 39 species were identified as native, while 13 were introduced. Two species are endemic to Thailand, Argyreia kerrii Craib and Argyreia leucantha Traiperm & Staples. The highest number of species bloom during the rainy season (June to August), with some flowering during the winter (January to March). This study identified three distinct growth habits: herbaceous vines, aquatic or semi-aquatic plants, and woody vines, shrubs, or prostrate and creeping herbs. Twenty-nine species were categorized as rare, while 23 were classified as common. Regarding conservation status, 44 species are listed as Not Evaluated (NE), six as Least Concern (LC), and two as Data Deficient (DD). The Convolvulaceae in Udon Thani Province are utilized for food, animal fodder, ornamental purposes, medicinal applications, and horticultural cultivation. This research represents the first comprehensive documentation of the Convolvulaceae family in Udon Thani Province, providing detailed information on biodiversity, conservation status, and traditional uses. The findings serve as a valuable resource for future studies on the region’s plant diversity and conservation efforts.