*3.2. Community Characteristics*

The vegetation of the area belongs to the Ostryo-Carpinion floristic zone. However, on the basis of the plot where the plant data analysis was made, *V. dingleri* occurs in specific degraded shrub communities, dominated by the woody species *Paliurus spina-christi*, which is a tree species with limited di ffusion. These communities consist of a loose shrub layer, dominated by the species *P. spina-christi*, *Olea europea* ssp. *europaea*, and *Quercus coccifera*, with a canopy cover of approximately 30% and a herb layer consisting of the species *Euphorbia dendroides*, *V. dingleri*, *Plantago bellardii*, and many species common in open, degraded, grazing areas of the Mediterranean zone, such as *Avena barbata*, *Allium sphaerocephalon*, *Capsella bursa-pastoris*, and *Bromus tectorum* (the full record of plant abundance/dominance [15] is shown in Table 2). All the recorded species are native, and no exotic species were found. On the basis of the above-mentioned vegetation data, the habitat type where *V. dingleri* was found could be classified as that of the eastern Balkan association *Euphorbio–Paliuretum* or *Oleo sylvestris–Paliuretum spinae christi* [27]. Further data are required for a full phytosociological analysis.


**Table 2.** Full list of flora taxa recorded in the communities where the species *V. dingleri* was found. The modified abundance/dominant scale according to the Braun–Blanquet method [17] was used.

#### *3.3. Fruit and Seed Diversity*

The fruit of *V. dingleri* is a capsule with a diameter of 3–4 mm (mean value 3.24±0.06 mm). The fruits ripen mature from late July to August and then turn green to brown-yellowish. The capsule is generally globose to sub-globose in shape (Figure 2b), and usually two-loculed, with each locule containing approximately half of the fruit's numerous seeds. The average number of fully developed seeds per fruit is 58.18 ± 3.37 (n = 64 fruits), ranging from 15 to 114 (Table 3). Few seeds (3.04 ± 0.86 per fruit) are abnormal (or not fully developed). Statistical analysis revealed significant differences between the three fruit classes in the number of normal seeds and abnormal (or not fully developed) seeds per fruit. In addition, a correlation procedure showed that the number of normal seeds per fruit was significantly positively correlated with the fruit size, i.e., the larger fruit, the higher the number of normal seeds and the lower the number of abnormal seeds (Tables 3 and 4).

**Table 3.** Fruit and seed characteristics of *V. dingleri* per fruit class. The values are means ± standard error of the mean. Fruit class: Class 1, fruits with diameter (d) > 3.5 mm; Class 2, fruits with 3.5 mm > d > 3.0 mm; Class 3, fruits with d < 3 mm. Means of the same columns followed by different letters are significantly different; ns, non-significant differences.



**Table 4.** Results of the statistical analysis for fruit and seeds of *V. dingleri*.

Note: \*\* Correlation is significant at the 0.01 level (two-tailed); b cannot be computed because at least one of the variables is constant.

The seeds are very small (minute), ovoid to polygonal, with surface ripples. Mature seeds are dark brown in color (Figure 2c), and their average length is 0.633 ± 0.014 mm. Their mean fresh weight is 4.8 × 10−<sup>4</sup> g, which defines them as small seeds. No significant differences were found in seed size between the three fruit classes. The average moisture content of fresh seeds was 26.7% of dry mass, and there was a tendency toward slightly higher values in the larger fruit classes. The seed dispersion of the species is barochory and ornithochory in nature; thus, considering the light seed mass, it is anticipated that species dispersion occurs to some distance from the mother plants.

#### *3.4. Seed Germination Behavior*

The germination percentage of *V. dingleri* seeds varied across different fruit classed in laboratory conditions. The best final germination percentage (40%) was observed for smaller seeds belonging to Class 3 (fruit diameter < 3 mm), (Figure 3 and Table 5). Seeds from Classes 1 and 2 showed a quite

similar germination pattern, and their final germination percentage was 32% and 26.7%, respectively. However, the fruit size, more specifically, the fruit diameter, does not affect the seed germination percentage of the species. The statistical analysis did not reveal any significant differences among germination percentages. The seeds from all fruit classes started to germinate seven days after sowing, and the germination progress stopped after six weeks. However, most seeds germinated within a period of four weeks, a common period for many species. The mean time to complete germination (MGT) ranged from 17.8 to 24.7 days and was not significantly affected by the fruit class.

**Figure 3.** Cumulative germination percentage curves of *V. dingleri* seeds as a function of time for the three fruit classes. Number of seeds: four replications of 25 seeds per fruit class.

**Table 5.** Seed germination behavior per fruit class in laboratory conditions (final germination percent and mean time to complete germination, MGT) and at nursery (ambient) conditions (percentage of fully developed seedlings) of *V. dingleri*.


Approximately 30 days after planting, in the middle of spring (April 2017), in ambient conditions, *V. dingleri* germinated seeds produced fully developed seedlings; however, their growth was slow and very similar for all produced plants (statistical analysis did not reveal significant differences among fruit classes, *p* > *0.05*) (Table 5). The percentage of fully developed seedlings of *V. dingleri* ranged from 2% to 30% among the fruits, regardless of the fruit diameter.
