Panarctic Flora


342007 Calamagrostis inexpansa A. Gray


Western Alaska: Scattered
Northern Alaska - Yukon: Scattered
Central Canada: Rare
Hudson Bay - Labrador: Rare
Western Greenland: Scattered
Eastern Greenland: Rare
Southern Arcti Tundra: Rare
Shrub Tundra: Rare
Bordering boreal or alpine areas: Frequent


2n= (1) 42 (6x). - Alaska. - Mitchell and McKendrick (1975).
(2) 56 58 (8x). - Far East, Alaska, Canada, U.S.A. - At least five reports.
(3) 63 (9x). - Alaska. - Mitchell and McKendrick (1975).
(4) 70 (10x). - Far East, Canada. - At least three reports.
(5) 84-ca. 120 (12x-ca. 17x). - Alaska, Canada, U.S.A., Greenland. - At least five reports.
Not included: Reports of tetraploids (2n = 28) from Califormia (Nygren 1954b, 1958), northern and southern Alaska (Mitchell and McKendrick 1975, three counts), and Russia (Sokolovskaya and Probatova in Tzvelev 1976). We are reluctant to accept tetraploids in this species.

Geography: Amphi-Pacific/Beringian - North American: ALA CAN GRL.

Notes: Calamagrostis inexpansa is reported from northeastern Asia but apparently does not reach the Arctic on the Asian side of the Bering Sea.

If C. inexpansa is a high polyploid derivative of C. neglecta and perhaps other tetraploids, the reports of tetraploids should be critically checked against vouchers. In the material we have assigned to C. inexpansa, the anthers (when present) are invariably aborting. Greene (1980, 1984) considered C. inexpansa a subspecies of C. neglecta but generally with higher chromosome numbers and at least partly with asexual reproduction. He interpreted it (Greene 1980) to have "developed from the sexual subsp. stricta through intra and inter-specific hybridization and polyploidy" and he suggested C. lapponica to be part of the parentage. The latter supposition is improbable as C. lapponica is invariably reported to be pollen-aborting and agamospermous (but with a few reported tetraploids!). See Greene (1980, 1984) for additional information. Greene's views were followed by Soreng and Greene in Soreng et al. (2003).

Greene (1980) assumed C. hyperborea to be a synonym for C. inexpansa but he did not study the Greenland type material. The name C. hyperborea has, according to him, been applied in North America only for plants belonging to C. inexpansa. Our study supports Greene's assumption. Greenland material of C. hyperborea falls within the morphological range of the variable North American C. inexpansa (comparison of specimens in ALA, O, and S). These two names were implicitly synonymized by Hultén (1968a) when he mapped C. inexpansa to occupy the Greenland range of C. hyperborea (which he did not mention by name).

Higher Taxa