Intraspecific taxa of the Russian thistle (Salsola kali L.)

Plants belonging to Salsola genus are annuals or dwarf shrubs glabrous or pubescent. Their leaves are filiform or semicylindrical, alternate or opposite. The flowers are hermaphroditic with two conspicuous bracteoles. There are 5 perianth-segments (3 outer and 2 inner), usually developing a transverse wing on the fruits; are 5 stamens and 2 (3) stigmas. The seeds are usually horizontal. Most species are restricted to more or less saline, sandy habitats, either in maritime or inland in arid regions. A large proportion is essentially Asiatic and they occur only on the extreme South-East margines of Europe. Salsola kali L.: erect or diffuse, glabrous or hispid annual up to 100 cm. The leaves are 10-40 mm long, linear-subulate, acuminate. Bracts are patent, bracteoles ovate-triangular, with long spine-like apex, longer than the flowers. Perianth segments are ovate, acuminate, usually with ovate to reniform wing. Stigmas are longer than the style. It occurs often on non-saline sands or as a ruderal. It extends throughout most of Europe northwards to 63x 30' North, but is in the north almost exclusively coastal. A polymorphic species, comprising many subspecies and varieties. In Europe at least 3 subspecies can be recognized. a) Perianth segments are stiff, more or less spinose. The plants are usually hispid: subs. kali. Distribution: maritime coast of Europe, northwards to 63x 30'. b) The plants are grey-green, glabrous or shortly hispid, bracteoles are not swollen, free, perianth-segments are usually winged: subsc. ruthenica (Iljin) Soo (Syn. S. iberica and S. pestifer). Distribution: throughout the range of the species, but often only casual in the north. c) The plant is yellowish, glabrous, bracteoles are swollen and at their base more or less connate; perianth-segments not winged: subsp. tragus (L.) Nym. (Sy. S. tragus). Coast of South Europe