Anemone reflexa (Steph.) Holub. - windbreaker bent - is short vegetative early spring perennial root grass from the ranunculaceous family (Ranunculaceae) It is listed in the Red Book of Perm Region (2008), the Red Book of Chelyabinsk Region (2008), and the Red Book of Sverdlovsk Region (2005). It is a feature element of dark for-ests, dominating along with Altai windbreaker bent in the field stratum in spring. In recent years, dark trees in taiga have been extensively cut down, which constitutes a threat to the extinction of the species. The purpose of the research was to as-sess the modification variability and seed productiv-ity of A. reflexa populations growing in the southern part of Krasnoyarsk Region and on the southeast-ern coast of the Lake Baikal. The object of our re-search was 15 populations of A. reflexa. While as-sessing phytocenotic confinement, it was revealed that windbreaker bent is widespread in the Eastern and Western Sayan, on the southeastern shore of Lake Baikal in birch, aspen, pine, fir and mixed for-ests, as well as on floodplain and cutover patches areas. Projective cover of A. reflexa in plant com-munities varies from less than 1 to 30 %, and the density varies from 19 to 62 shoots per 1 m2. In plant communities the species take the roles of an assectator and a codominant. The maximum sizes of vegetative organs, real seed productivity (14.7-18.3 pieces of formed fruit per a reproductive shoot) and high values of the coefficient of seed formation (86.4-88 %) were noted for Sayan popu-lations growing in dark woods. Unfavorable condi-tions for seed reproduction of the windbreaker bent are noted for the populations growing on small dis-tance from Krasnoyarsk. On cuttings down the in-crease in level of intra population variability of mor-phological features is noted, however reliable de-crease in the sizes of vegetative bodies is recorded only on the cuttings down presented by meadow phytocoenosis.