**1. Introduction**

Over the last decades, many plant species have been threatened as a consequence of several anthropogenic disturbances and climate change that resulted in species habitat loss. Especially, species with very limited distribution ranges, specific site requirements, and small populations are at high risk of extinction [1].

Unfavorable site conditions for species self-reproduction and seedling development in natural or human-disturbed habitats may cause di fficulties in species ecological status and future prospects [2–4]. Thus, data on seed ecology and species regeneration requirements are of grea<sup>t</sup> importance.

Early phases of plant life such as germination, seedling development, and early growth are very important stages in plant life cycle and greatly vary in space and time, especially for species of limited

populations [5,6]. These stages are commonly a ffected by many endogenous (lethargy or desiccation tolerance) and exogenous (e.g., site conditions) parameters that greatly threaten species life [7,8]. Successful seed germination and seedling propagation are key factors for ex situ species conservation and in situ species restoration [9,10].

*Verbascum dingleri* Mattf and Stef. is a rare Greek plant species that belongs to the family Scrophulariaceae, with extremely narrow geographical distribution in northern Greece [11–14]. According to the available information, its presence worldwide has been recorded only three times [12] in two localities, as reported in the Global Biodiversity Information Facility (GBIF) Backbone Taxonomy Checklist Dataset (https://doi.org/10.15468/39omeiassessed via GBIF.org): one time, near Chrysoupolis in 1936, in a location with coordinates 40,98 N, 24,70 E, at an altitude of 150 m above sea level, and two times, in Toxotes, close to the first record (at a distance of 15 km) and at the same elevation, on limestone. The first species record was described by Mattfeld in 1926 [11]. Very few further records have been found in the Greek "grey" literature, but these were omitted in the manuscript. The high frequency of anthropogenic disturbances in the area where the species lives seems to a ffect the species conservation status. The target species population was located adjacent to a linear construction project which had commitments to mitigate biodiversity impacts. The commitments included seed collection for post construction habitat restoration initiatives.

In this study, the autecology of *V. dingleri* was investigated to provide a better understanding of the conservation of this species. The research was focused on determining the species distribution range and habitat area, community characteristics, population information, and reproduction abilities for in situ and ex situ conservation. More specifically, the study aimed at:


#### **2. Materials and Methods**
