Variability of the sexual reproductive part in stinging nettle <scp> <i>Urtica dioica</i> </scp> L. (Urticaceae): From flower to genet

Abstract Stinging nettle, Urtica dioica L., is a widely distributed subdioecious long‐rhizomatous plant. Within a single population growing in the territory of the Zvenigorod Biological Station of Lomonosov Moscow State University, eight plots were selected in stinging nettle thickets to study the variability of the sexual reproductive part in U. dioica depending on internal and external factors. As monoecious ramets are relatively common in the studied population, four gender forms were distinguished based on the ratio of male and female flowers. On 156 ramets of different gender forms and 36 genets, it was shown that predominantly male plants are shorter, while predominantly female plants have larger and more widely spread inflorescences compared to other gender forms. The pubescence type (spreading or appressed unicellular hairs) shows the greatest repeatability within the merigenet. True monoecy in stinging nettle is widespread: male and female flowers of different gender forms were found in 10 out of 36 genets. The most common inflorescence architecture types in the studied population were proxigynous and basigynous. Both normal pistillate and normal staminate flowers, as well as flowers with morphological abnormalities formed based on flowers of different sexes can be found on the same ramet, which suggests the presence of paradioecious lability.