ИСТИНА

The genus Semenovia is one of taxonomically complex genera in the tribe Tordylieae. The genus contains 29 species, distributed only in Asia (Middle Asia, Southwest Asia (from Iran to Pakistan), North India and China). Its greater diversity can be observed in the mountains of Pamiro-Alai and Pamir. Many species of the genus are narrow endemics or are known for few localities only. The genus was described in 1866 from the Zailiiskii Alatau (North Thian-Shan), with a single species S. transiliensis. According to morphological and molecular data, the genus Semenovia clearly differs from closely related genera Zosima, Pastinaca and Heracleum. Recently, new species were described, including Semenovia pulvinata, S. dissectifolia, S. imbricate and S. vachanica from Pamir, Tajikistan and Semenovia alaica, S. vaginata from the mountains of Pamiro-Alai. Three nomenclature combinations were suggested: S. torilifolia, S. malcolmii and Semenovia glabrior. With the help of the scanning electron microscope we have first investigated fruit micromorphology of 21 species of the genus. Chromosome numbers of 12 species were determined, of 9 species for the first time. For all species studied, 2n=22, however, for a high mountains belts species S.pamirica polyploidy (2n=44) was observed. As for their life form, all plants of the genus belong to a group of perennial herbs with taproots. The life form of type species S. transiliensis is monocarpic, with fusiform-tuberous root and solitary stem. Most species of Semenovia have a similar life form of polycarpics with entire or branched caudex and two or more stems. Characters of caudex states are the taxonomically important for the genus. Various characters of caudex are: underground, overground or emergent; single-headed or multi- headed; with short or long branches, dense or sparse. There are some marked differences among the species in rigid vs. soft petiole remains, covering caudex branches. Species with an overground caudex and long or short branches form cushions, filled or not filled.