Biology and distribution of Orchis purpurea subsp. caucasica (Regel) B. Baumann et al. (Orchidaceae Juss.) in the Sochi Black Sea region

Abstract

Orchis purpurea subsp. caucasica (Regel) B. Baumann, H. Baumann, R. Lorenz et Ruedi Peter is widespreadin the Sochi Black Sea region. It occurs on forest edges and in secondary woodlands of the lower mountain zone. Thenumber in individual populations is from 3 individuals to several dozen, occasionally there are clusters of up to 400individuals. The abundance varies greatly depending on the weather conditions and other factors. The species is winterlate-spring-green with a summer-winter dormant period. The growing season lasts 4–4.5 months. The criterion foridentifying ontogenetic states is the number and size of leaves, the number of leaf veins. Ontogenetic spectra of populationsare single-peaked with a predominance of adults; in more favorable growing conditions, two-peaked with a maximum ofjuveniles. Populations are full-member, normal type, stable. Seed renewal. Fruit formation is about 37.3 %. The numberof seeds in one capsule is from 6 to 28 thousand, one individual produces up to 80 thousand complete seeds per season.Orchis-type seeds, club-shaped, about 0.4 mm long; the embryo is large, round in projection. The species is protected inthe Caucasian State Natural Biosphere Reserve and the Sochi National Park.