218 Poa arctica R. Br.

This arctic-montane species includes here some lower taxa (excl. subsp. caespitans [Simm.] Nannf., see no. 219), viz. subsp. longiculmis Hult. and subsp. williamsii (Nash) Hult. in NW. North America and subsp. depauperata Nannf. in S. Norway and on lceland. For further information about the P. arctica taxa, see Nannfeldt in Symb. Bot. Ups. 4:4/1940. The species s. lat. belongs to the circumpolar plants. However, it is reported among the amphi-atlantic plants (Hultén, Amphi-atl., p. 24 and map 6), together with subsp. caespitans (op. cit., map 5). Cf. also Meusel et al. 1965, map p. 32.