A large genus of about 500 species wordwide, of which 100 in the FSU. One well-known species is V. altaica Ker-Gawl., native to Altay, Tien Shan, Dzungaro-Tarbagatay and northwestern China. V. hirta L., of wide distribution, is also in cultivation. Other species have been investigated. Unfortunately, most of them are short-lived plants. The following are among the long-lived.