English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Flower structures, especially the shape of the pistil with stigma, stamen appendages (nectaries) and pollen heteromorphism are important diagnostic features in the genus Viola L. The style characters were crucial in the very early classifications of this genus (Clausen 1927). We analyzed in details, using scanning electron microscopy (SEM), the microstructural characters of generative organs (style and stigma, stamens with nectaries) and pollen in representatives of three sections (Viola L., Melanium Ging., Dischidium Ging.) occurring in Poland to get insights into the relatedness among far-related (different sections) and closely related (sub-sections within section) species. There is a great difference in stigma micromorphology between sections. In the section Viola flowers have style beaked at the apex, glabrous or covered by papillae and/or hairs, depending of subsection. Monotypic section Dischidium with one species V. biflora L. characterizes 2-lobed stigma. Cup-shaped stigma with the hole on the top and a lip below, covered with papillae and hairs on its outer surface occurs in pansies of the section Melanium. Pollen is highly heteromorphic (different pollen morphs, from three up to six apertures within one flower or even within one pollen sac) in the Melanium section and weakly heteromorphic mainly with three apertures in diploids of Viola and Dischidium sections. This character is independent of the polyploidy in the Melanium but not in Viola section (Dajoz 1999). The flower micromorphological characters are also useful in reconstruction of closely related species origin. Based on stigma and nectaries features, two zinc violets are more similar to the alpine V. lutea, than to V. tricolor, indicated also as the ancestor (Kuta et al.2012)

Floral structure and pollen morphology are important characters in taxonomy of the genus Viola (Violaceae)