Panarctic Flora


342005 Calamagrostis holmii Lange


Kanin - Pechora: Rare
Polar Ural - Novaya Zemlya: Scattered
Yamal - Gydan: Frequent
Taimyr - Severnaya Zemlya: Frequent
Anabar - Onenyo: Frequent
Kharaulakh: Frequent
Yana - Kolyma: Scattered
West Chukotka: Frequent
Wrangel Island: Scattered
South Chukotka: Scattered
East Chukotka: Frequent
Western Alaska: Scattered
Northern Alaska - Yukon: Scattered
Central Canada: Rare
Mid Arctic Tundra: Rare
Southern Arcti Tundra: Frequent
Shrub Tundra: Frequent
Bordering boreal or alpine areas: Frequent

2n= 28 (4x). - Siberia (N), Far East (N), Alaska. - Several reports.
Not included: A report of 2n = 42 (6x) from northeastern Asia (Zhukova 1967a). This report should be checked against voucher.

Geography: European (NE) - Asian (N) - amphi-Beringian: RUS SIB RFE ALA CAN.

Notes: Elven, Murray, and Solstad: Hultén (1968a) mapped Calamagrostis holmii from northwestern and northern Alaska, possibly the northern Yukon Territory, and on the mainland coast of the Northwest Territories to east of the Mackenzie River Delta (see also McJannet et al. 1993). Porsild & Cody (1980) omitted C. holmii for the N.W.T. and Cody (1996) considered the name a possible synonym of C. neglecta. Soreng and Greene in Soreng et al. (2003) and Marr et al. (2007) synonymized C. holmii with C. neglecta (stricta) subsp. groenlandica.

Elven and Solstad studied both C. holmii and C. neglecta subsp. groenlandica in the field in Yakutia in 2004 and East Chukotka in 2005 and found that they could keep them apart on the characters proposed by Tzvelev (1976 and elsewhere). Transitional forms, except for pollen-sterile assumed hybrids, were not observed. Revision of material (ALA) in 2009 by Elven and Murray supported a North American range for C. holmii similar to that reported by Hultén (1968a), with several localities along the coasts, in the lowlands, and in the northern mountains from the Cape Thompson area in northwestern Alaska east to the northern Yukon Territory, and with hybrid plants farther east to the Mackenzie River Delta.

An equally large group of the North American samples showed morphological features intermediate between C. holmii and C. neglecta subsp. groenlandica. These plants had aborting anthers. In North America, C. holmii seems to be rare and to be surrounded by and mainly pollinated from the much more common C. neglecta subsp. groenlandica. Whether the resulting plants are seed-sterile primary hybrid clones or reproduce by agamospermy is not known, but we have not observed seed-set in the material. If they reproduce and need a name, the name C. chordorrhiza A.E. Porsild is available. A topotype (ALA) of C. chordorrhiza from "Reindeer Station" in the Mackenzie River Delta combines characters of C. holmii and C. neglecta subsp. groenlandica and has aborting anthers. Therefore, we do not synonymize the name C. chordorrhiza with C. inexpansa as done by other authors.

Higher Taxa