Panarctic Flora

342609a Poa pratensis subsp. pratensis

2n= 28-ca. 124 (4x-ca. 18x). - Northern Hemisphere throughout. - Numerous reports. Proposed ranges: 18 [28]-ca. 124 (Conert 1998), 52-70 (Tzvelev PAF proposal).

Geography: European - Asian?: ICE* NOR* RUS SIB RFE ALA* CAN* GRL*.

Notes: Subspecies pratensis is considered in northwestern Europe and North America mainly as a temperate and southern boreal plant. It is not considered native in the middle and northern boreal parts of Fennoscandia (e.g., Hylander 1953b; Elven 1994; Hämet-Ahti et al. 1998; Elven et al. 2005). However, it is among the most frequently used forage grasses and is introduced regularly in northern regions. Also strains of subsp. alpigena (and partly of subsp. irrigata) are extensively cultivated for forage in the north and are much more persistent there than subsp. pratensis, which means that adventive Poa pratensis in these areas more often is subsp. alpigena (and subsp. irrigata) than subsp. pratensis. All plants we have inspected from Greenland, Svalbard, and the arctic parts of mainland Norway - also the adventive ones - are excluded by us from subsp. pratensis. However, due to frequent reports, subsp. pratensis is tentatively given as an established adventive.

Note the discrepancy in distribution above and in the distribution table. Subspecies pratensis is assumed to be native in all Russian areas (e.g., Sekretareva 1999) and to be adventive in all non-Russian ones. We have seen no subsp. pratensis, as we Europeans would accept it, in the field in the arctic parts of Russia. Different characters may have been applied for its recognition. We suspect that the frequent acceptance of subsp. pratensis as arctic in Russia, and partly in North America, may be due to a more narrow circumscription of subsp. alpigena than we currently apply. Internal note: Our current character set applied for separation between subsp. pratensis and subsp. alpigena should be re-evaluated. The way it divides the material is not convincing.