The genus Trollius (Ranunculaceae) in the Russian Far East

1 I. M. Sechenov First Moscow State Medical University, Izmailovsky Boulevard, 8, Moscow, 105043, Russia. E-mail: luferovc@mail.ru 2 Central Siberian Botanical Garden, SB RAS, Zolotodolinskaya str., 101, Novosibirsk, 630090, Russia. E-mail: erst_andrew@yahoo.com 3 Tomsk State University, Lenina pr., 36, Tomsk, 634050, Russia 4 Moscow Region State University, Radio str., 10A, Moscow, 105005, Russia. E-mail: dimnikluf@mail.ru 5 Altai State University, Lenina pr., 61, Barnaul, 656049, Russia. E-mail: bot@asu.ru 6 Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China. E-mail: wangwei1127@ibcas.ac.cn 7 University of Chinese Academy of Sciences, Beijing, 100049, China *The corresponding author: erst_andrew@yahoo.com


Introduction
The genus Trollius includes с. 35 species distributed in the extra-tropical regions of Northern Hemisphere. In Russia about 19-20 species are recognized. Trollius ledebourii Reichenb. is used in folk medicine to treat epilepsy (Vostrikova, 1973); T. chinesis Bunge has antibacterial (Lin et al., 2001;Lu et al., 2015), antiviral (Li et al., 2002;Cai et al., 2006) antioxidant and antitumor (Song et al., 2013;An et al., 2015) effects. Other species of the genus can also be used for medicinal purposes.
The territory of the Russian Far East contains 6 species (Woroschilov, 1982) or 8 species of Trollius (Luferov, 2004). Based on Woroschilov (1982), the territory of the Far East is characterized by monsoon climate and does not include the West of the Amur region, the Khabarovsk territory, and Arctic and subarctic areas of the Magadan region and the Chukotka Peninsula. Luferov (1995Luferov ( , 2004 considered the Russian Far East as its administrative boundaries, which is also the floristic zoning scheme suggested by S. Kharkevich (1985).
Species of the genus Trollius are perennial herbs with short rhizomes and numerous adventitious roots, simple or branched hollow stems. At the base of aboveground shoots, there are scale-like leaves and fibrous remnants of leaf petioles. Photophilic leaves are palmatipartite or palmatisecte and their margins are scallop-serrate or cut-serrate. Flowers are solitary or assembled in a monochasium inflorescence, termed gyrus. Calyx is corolla-shaped. Sepals have 5 to 20-30; different species have orange, yellow, lemon yellow, almost white or creamy white. Petals amount to 5-20 in number; they are linear, lanceolate, lobed, or obovate, and nectarous fossa at the base. The ovary is unilocular. Ovules are arranged linearly. The fruit is multifolliculus and opens from the ventral side.
The main problem of taxonomic study of Trollius is that the diagnosis of species usually rests upon the peculiarities of the structure of flowers. Structural features of vegetative organs and fruits were paid less attention. Besides, a small number of distinctive features were taken into account and little attention was paid to the variability of plants collected in different habitats and their different parts.
With the view to determine species and subspecies we used a set of structural characteristics of vegetative and generative organs: height of abovethe-soil shoot; shape, sizes and degree of dismemberment of leaf blades; shape, sizes and number of sepals, petals, stamina, the ratio of their lengths; sizes and number of fruitlets; length of stylodia and other features (Siplivinsky, 1972;Doroczewska, 1974;Kadota, 1987;Luferov, 1995).
The main aim of this work was to study the taxonomy and characteristics of the Trollius species in the flora of the Russian Far East. We first identify morphological characters of the Trollius species of the Far East as diagnostic ones, make up the key for identifying species, and analyze the distribution of Trollius species in Far East of Russia. The importance of the undertaken research can be seen both in getting to know the biodiversity of this genus in the Russian Far East and in the practical relevance of its representatives as sources of biologically active compounds.

Methods
In this study, we followed the Russian Far East within its administrative borders, including the Amur, Kamchatka, Magadan, Sakhalin Regions, Khabarovsk and Primorsky Territories. Morphological and geographical methods of the research have been used. The specimens desposited in the following herbarium collections: V. L. Komarov Botanical Institute (LE), the Main Botanical Garden (MHA), M. V. Lomonosov Moscow State University (MW), Institute of Biology and Soil (VLA), were examined. Meanwhile, living plants were also collected during 10 expeditions (1980,(1986)(1987)(1988)(1989)(1990)(1991)(1992)(1993)2015) in the Sakhalin Region (Sakhalin Island, the Islands of Iturup and Kunashir), and Khabarovsk and Primorsky Territories.

Conclusion
The study presents the taxonomic and geographic characteristics of 9 species of Trollius (Ranunculaceae) in the Russian Far East. The suggested key is based on a combination of vegetative and productive morphological characters. For the first time on the territory of Russia (the Kuril Islands: Iturup, Kunashir) Trollius japonicus Miq. was recorded. It is shown that the previously known information on the distribution of this species on Sakhalin Island is based on incorrect identification. The data can be used for further studies of Trollius species as perspective medicinal plants.