Solving the problems of preservation and rational use of plant genetic diversity is one of the main tasks for botanical gardens and scientific institutions working in this field. In the Subtropical Scientific Centre of the Russian Academy of Sciences, the collection of natural species of the genus Iris has been formed since 2000s. The paper presents research results on the following 11 species: Iris colchica Kem.-Nath., I. ensata Thunb., I. japonica Thunb, I. orientalis Mill.,I. notha M. Bieb, I. pallida Lam., I. pseudacorus L., I. pseudonotha Galushko, I. sibirica L., I. spuria L., I. unguicularis Poir. Most of the species are rare (6), rare and endemic (2). As a result of the studies conducted in 2020-2022, flowering terms for the irises species in collection have been established in the humid subtropics of Russia and 4 groups have been recorded. The first group with the earliest flowering (April, early May) includes I. japonica, I. sibirica. Average flowering terms (from mid-late May) are recorded for I. orientalis, I. colchica, I. pallida, I. pseudacorus. Late flowering terms (from late May - early June) are recorded for I. notha, I. pseudonotha, I. ensata. Late autumn-early winter periods - for I. unguicularis.