Panarctic Flora

341602 Deschampsia alpina (L.) Roem. & Schult.

• Roem. & Schult., Syst. Veg. 2: 686 (1817). - Aira alpina L., Sp. Pl.: 65 (1753). Neotype (BM): Sweden: Torne lappmark, Mount Njuolja, 25. July 1950, leg. N.D. Simpson 50133 (Cope in Cafferty et al. 2000: 293). - Deschampsia cespitosa subsp. alpina (L.) Tzvelev, Fl. Sev.-Vost. Evrop. Chasti SSSR 1: 209 (1974) comb. illeg., see notes.

2n= 39-56 (3x-ca. 4x). - Europe (N), Russia (N), Greenland. - Numerous reports.
Löve and Löve (1975a) 'corrected' the reports they cited so as to fit a uniformly tetraploid (2n = 52) concept of D. alpina, while they indicated that plants under this name but with 2n = 39 (and also 26) could be hybrids. The 2n = 52 or 56 counts are in a minority in D. alpina (ca. 30%). The plants of the Scandinavian mountains (type region) and those of Svalbard that fit the diagnostic characters of Linnaean D. alpina have been counted at 2n = ca. 39, 41, 49, and 50. In many areas, there is no possibility of this variation being due to recent hybridization as D. alpina is the only species of Deschampsia present.
Not included: We suspect that reports of 2n = 26-29 (Nygren 1949a; Sokolovskaya and Strelkova 1960; Albers 1980) may stem from occasionally viviparous D. cespitosa or other 'diploids'.

Geography: Amphi-Atlantic: ICE NOR RUS CAN GRL.

Notes: The amphi-Atlantic, bulbil-reproducing Deschampsia alpina differs from D. cespitosa in more characters than the bulbils, e.g., smooth panicle branches (vs. rough) and short, regularly involute blades with nearly smooth ribs (vs. mostly flat and very rough). Deschampsia alpina is therefore separable from the occasional bulbil-producing forms or mutations of D. cespitosa. Deschampsia alpina may be an autopolyploid derivative of D. cespitosa with secondary spread westwards across the North Atlantic, or an allopolyploid and agamous hybrid species, perhaps with D. brevifolia as the other parent (the characters that distinguish it from D. cespitosa are shared with D. brevifolia). The range of D. alpina overlaps with that of D. brevifolia in Greenland and Canada, with that of D. cespitosa in northern Europe and Iceland. There is no overlap today of the native ranges of D. brevifolia and D. cespitosa. The only other Deschampsia known from the same regions, D. sukatschewii subsp. borealis, is more different morphologically in both vegetative and generative characters and is an unlikely parent. The hybrid origin hypothesis for D. alpina needs to be tested by molecular means. Material from Canada, Greenland, Svalbard, Iceland, mainland Scandinavia, and Russia has been compared and found to be essentially similar. We assume that only one taxon is present.

There are two meanings of the name "alpina". One is based on Aira alpina L., now with a specified type from northern Sweden (see above). According to Chiapella et al. in Soreng et al. (2003), Linnaeus' name and meaning is applicable and has priority at the rank of species, but the combination Deschampsia cespitosa subsp. alpina (L.) Tzvelev 1974 is illegitimate due to D. cespitosa var. alpina Schur 1859, described from the Carpathians. ICBN (McNeill et al. 2006: article 53.4) defines these two names as homonyms. Chiapella et al. in. Soreng et al. (2003) applied Schur's varietal name to the arctic plants. We do not accept this. European authors regard the arctic plant as narrowly amphi-Atlantic and do not accept it to reach central Europe (the Carpathians), see Hultén (1958: map 203). We consider D. alpina a morphologically separable species (see above) and different from occasional bulbil-producing D. cespitosa. Schur's "alpina" is probably based on such occasionally sprouting D. cespitosa. If the northern plant is to be named as a subspecies, it must therefore have a new name. Barkworth (2007b) accepted the arctic American plants as D. alpina.