Flora of Mayorsky Mountain Massif of Susunay Ridge (Southern Sakhalin)

The local flora of vascular plants of Mayorsky Mountain Massif of Susunay Ridge in the southern part of Sakhalin Island contains 230 species from 171 genera and 71 families. For the first time, 50 species are listed for the massif. The flora of serpentinite outcrops is especially specific. Plant communities on the serpentinites are dominated by species with wide geographical areas (circumpolar, Eurasian, Asian and East Asian), whose share is more than 70% of the total local flora, which is a reflection of the geological past in the process of the alpine flora formation on Sakhalin Island. There are 64 species concentrated on an area of about 0.4 ha (Bistorta pacifica, Leontopodium discolor, Malaxis monophyllos, Rubus pedatus, Thesium refractum, Tofieldia coccinea and others), of which three species (Carex capillaris, Cerastium sugawarae and Pedicularis chamissonis) are found nowhere else on Sakhalin. The nearest localities of isolated populations of subalpine and alpine species on serpentinite outcrops (Carex melanocarpa, Loiseleuria procumbens, Rhododendron parvifolium, Scirpus maximowiczii) are in the northern part of Sakhalin or in the Northern Japan. Mayorskaya Mt. is the locus classicus of Poa sugawarae and Cerastium sugawarae. An annotated checklist of vascular plants is given. The modern flora of Mayorsky Massif is a reflection of paleogeographical history and climate fluctuations.