Home – Home – Jornals – Flora and Vegetation of Asian Russia 2021 number 3

Morphological characters of stigmas in 26 Asian and North American species of the genus Mertensia Roth (Boraginaceae) were studied using a scanning electron microscope. It is noted that there are 3 types of stigmas in the genus: flat, with a depression in the center; weakly or noticeably bi-lobed and spherical. In most species of the genus Mertensia, papillae have a short, barely noticeable stem and a lobed or spherical cap. We have designated this form of papillae with a new term - “modified lageniform” (modified bottle-shaped). For two species of the subgenus Steenhammera (Reichenb.) O.D. Nikif. characteristic papillae are “vermiform” (worm-like). The shape of the papillae confirms the earlier conclusion about the relationship of the North American species M. virginica (L.) G. Don fil. and Altai endemics M. bracteata (Willd. ex Schult. et Roem.) R. Kam. and M. meyeriana Macbride. It is shown that M. sibirica stands alone in the type sub-section of the Mertensia section, but shows kinship to the North American species M. arizonica Greene. In the species of the section Pterocarpeae Popov ex O.D. Nikif. papillae have a unique shape (4-8 multi-lobed deeply dissected caps with smooth surface), which confirms the validity of their inclusion in an separate section. In the section Alpinae O.D. Nikif. the papillae shape of the of M. lanceolata and M. longiflora differs from the other studied species of the section. It is shown that the features of papillae correlate with the features of the sectional and subsectional rank and can be used in the taxonomy of the genus.