About the species of relationship Mertensia sibi (Boraginaceae)

The taxonomic position of three Asian species Mertensia sibirica (L.) G. Don fl., M. bracteata (Willd. Ex Schult.) R. Kam. (= M. pallasii (Ledeb.) G. Don fl.) end M. meyeriana Macbride (=M. popovii N. Rubtz.) are discussed. These species are included in the type subsection of the genus Mertensia Roth (Boraginaceae), which is divided into two seriestype Mertensia and the series Sibiricae Popov ex O. D. Nikif. The species M. bracteata is included in the type series, and two other species are assigned to the series Sibiricae. M. sibirica is distributed mainly in Eastern Siberia and has the widest range, and M. bracteata and M. meyeriana are narrow-local endemics to the Altai mountain country. The morphological differences of related species are discussed and the keys for determining the Asian species of the Mertensia subsection are given.For each species, a nomenclature citation, type sample, distribution and ecology are indicated.