A taxonomic revision of Iris section Psammiris (Iridaceae) in Russia

Until now, as few as 2-4 species of the genus Iris sect. Psammiris (Iris bloudowii, I. humilis, I. mandshurica, and I. potaninii) have been reported in Russia in botanical publications. We have analysed the diagnostic value of morphological characters. At the series level, features of the root system, the shape of basal leaves, the height of flowering scape, and the length of perianth tube are most significant. The shape and size of spathes are also usable for species identification. In the present contribution, a synopsis of I. sect. Psammiris in Russia is presented, including the description of a new series, Vorobievia. In that country, the section comprises 7 species belonging to 3 series and occurring mainly in Siberia and the Far East, one species extending to the Eastern Europe. A key for species determination is compiled, and the distribution areas of the accepted species are specified. Types are indicated for all involved names, two of which (lectotypes) are designated here. Furthermore, previous results of molecular studies including taxa in this section are analysed and discussed, which demonstrate that I. sect. Psammiris is indeed monophyletic according to the morphological and molecular data available so far.