341606 Deschampsia sukatschewii (Popl.) Roshev.
- Roshev., Fl. URSS 2: 246 (1934). - Aira sukatschewii Popl., Och. Fitosots. Fitogeogr.: 382 (1929). Lectotype (LE): Siberia: "Transbaicalia inter fl. Nercza et fl. Kuenga; ad ripam fl. Olov prope pag. Olov", 13. July 1911, leg. Sukatchew and Poplavskaja 1790 (Tzvelev 1976: 282).
Geography: Circumpolar & Asian (C).
Notes: Elven and Aiken: Tzvelev (PAF proposal) considered Deschampsia sukatschewii s. lat. a major boreal and arctic species with three subspecies. We accept this as perhaps the best solution today. The plants assigned here are characterized by, e.g., leaves narrow and often convolute with smooth upper surface, spikelets small, callus hairs conspicuously long compared with other species, and some characters in awn attachment and exsertion.
Several names are available in this complex. At species level, Aira sukatschewii Popl. 1929 has priority before Deschampsia paramushirensis Honda 1930 and D. borealis Roshev. 1934. The often applied name of D. pumila (Griseb.) Ostenf. 1923 is a later homonym of the Caucasian D. pumila Fomin & Woronow 1907 and must be replaced (see notes to subsp. borealis below).
As circumscribed by Tzvelev, D. sukatschewii becomes the most wide-ranging arctic species besides D. brevifolia, with a Siberian subsp. sukatschewii, a widely amphi-Beringian and North American subsp. orientalis, and a probably arctic circumpolar subsp. borealis. Chiapella et al. in Soreng et al. (2003) were of another opinion. They treated D. sukatschewii subsp. sukatschewii as doubtfully present in North America, subsp. orientalis as doubtfully present along the arctic coasts, and subsp. borealis as possibly present only on the Bering Sea islands. This must mean that they included both the main arctic sea coast plants and the tundra plants commented on by Aiken below (under subsp. borealis) in their concept of subsp. cespitosa. We disagree with that view. Barkworth (2007b) accepted a widespread D. sukatschewii for North America and Greenland and stated that: "Efforts to circumscribe infraspecific taxa of D. sukatschewii for this treatment failed." She may well be right.
Chromosome number reports assigned to D. sukatschewii include diploids, triploids, and tetraploids. Other species may be involved in the origin of the triploids and tetraploids and may be a reason for the problems in clearly circumscribing a species and separation of races.