13 Equisetum variegatum Schleich.

Within this variable, Eurasiatic and N. American species several lower taxa are distinguished. Among them var. jesupi A. A. Eat. in eastern N. America and subsp. alaskanum (A. A. Eat.) Hult. in the coastal area from Alaska to Washington are specially registered on the map. For other taxa see int. al. Hultén, Circumpol. I, p. 52. The species belong to the circumpolar plants (1. cit. and map 45).