Features of pubescence of mericarps of some species of the genus Geranium. Trichomes classification

The features of pubescence of mericarps in 34 taxa of species and intraspecific ranks of the genus Geranium from different sections were studied. Based on the studied materials, a classification of trichomes on the surface of mericarps has been developed. Two groups of trichomes have been distinguished: non-glandular, including three types and six subtypes, and glandular, including one type and four subtypes. For the first time, non-glandular simple unbranched ribbon-like trichomes (LP), non-glandular complex uniserial unbranched hooked trichomes (CrS), non-glandular complex uniserial unbranched helical trichomes (BC), non-glandular complex uniserial branched filamentous arachnoid trichomes (PS), long glandular capitate unbranched complex trichomes with big head (GLb). The types of mericarp trichomes were analyzed according to their occurrence in different sections of the genus Geranium. It has been shown that there are types of trichomes that are characteristic of the mericarps of the species of most sections, and types of trichomes that are characteristic of the mericarps of species of one or two sections, or even one species from the sections. This is the basis for considering some characters of trichomes as a specific and sectional characters. At the same time, this issue requires further study of the surface of mericarps of representatives of other species, both from the already studied sections and from new sections.