740105b Rhododendron tomentosum subsp. decumbens (Aiton) Elven & D.F. Murray
Distribution
Kanin - Pechora: Presence uncertain
Polar Ural - Novaya Zemlya: Presence uncertain
Yamal - Gydan: Frequent
Taimyr - Severnaya Zemlya: Frequent
Anabar - Onenyo: Scattered
Kharaulakh: Frequent
Yana - Kolyma: Frequent
West Chukotka: Frequent
Wrangel Island: Rare
South Chukotka: Frequent
East Chukotka: Frequent
Western Alaska: Frequent
Northern Alaska - Yukon: Frequent
Central Canada: Frequent
Hudson Bay - Labrador: Frequent
Ellesmere Island: Rare
Western Greenland: Frequent
Mid Arctic Tundra: Rare
Southern Arcti Tundra: Frequent
Shrub Tundra: Frequent
Bordering boreal or alpine areas: Frequent
- Elven & D.F. Murray, J. Bot. Res. Inst. Texas 2: 441 (2008). - Ledum palustre var. decumbens Aiton, Hort. Kew. 2: 65 (1789). Described from the Hudson Bay area (Canada). - Ledum decumbens (Aiton) Lodd. ex Steud., Nomencl. Bot., ed. 2, 2: 20 (1840). - Ledum palustre subsp. decumbens (Aiton) Hultén, Fl. Kamtchatka 4: 8 (1930). - Rhododendron subarcticum Harmaja, Ann. Bot. Fenn. 27: 203 (1990). Nomen novum for Ledum palustre var. decumbens. - Rhododendron tomentosum subsp. subarcticum (Harmaja) G.D. Wallace, Madroño 39: 77 (1992) comb. illeg..
2n=
(1) 26 (2x). - Far East (N), Alaska. - Zhukova (1980); Johnson and Packer (1968).
(2) 52 (4x). - Far East (N), Canada, Greenland. - At least five reports.
The Johnson and Packer (1968) diploid chromosome count from northwestern Alaska (for Ledum palustre s. lat.) was entered by Löve and Löve (1975a) as L. groenlandicum, probably because it did not fit with the other counts of L. palustre. Alaskan plants of the two species are not easily confused and Rhododendron groenlandicum is not known as far west as the area in question (Ogotoruk Creek, see Hultén 1968a). A voucher should be checked before acceptance. However, the report is made more probable by a report of a diploid from South Chukotka (Zhukova 1980).
Geography: Asian (N/C) - amphi-Beringian - North American (N): RUS? SIB RFE ALA CAN GRL.
Notes: Occurrence of subsp. decumbens in northern European Russia remains to be convincingly documented.
Harmaja (1990) considered this taxon a species and coined the nomen novum Rhododendron subarcticum with Ledum palustre var. decumbens as its typonym, due to the previously described R. decumbens D. Don ex G. Don, Gen. Hist. 3: 846 (1834). Wallace (1992) rather considered it a subspecies, like we do, and recombined it as subsp. subarcticum, probably unaware that the epithet "decumbens" has priority at level of subspecies also in Rhododendron.
Higher Taxa
- Rhododendron tomentosum [740105,species]