Anthoxanthum monticola

(Bigelow) Veldkamp
Common names: Alpine sweetgrass Hierochloé alpine
Treatment appears in FNA Volume 24. Treatment on page 760.
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Plants perennial; densely to loosely cespitose, rhizomes to 2 cm long, rarely longer, about 2 mm thick. Culms 20-55(75) cm. Basal sheaths glabrous, brown to deep purple; ligules 0.2-1.5 mm, truncate, ciliate; blades 1-12 cm long, (0.7) 1-3(5) mm wide, flat or folded, abaxial surfaces glabrous and shiny, adaxial surfaces sparsely scabrous or pilose. Panicles 1-8.5 cm long, 1.2-2 cm wide, with (3)10-20(35) spikelets. Spikelets 5-8 mm, tawny; rachilla internodes about 0.1 mm, glabrous. Glumes subequal, 4.8-6.7 mm, about equal to the lemmas; lowest 2 florets staminate; lemmas 4-6.5(8) mm, moderately hairy, hairs to 1 mm, apices deeply bifid, first lemma awn 0.6-4(6.5) mm, second lemma awn 4.5-10.5 mm, usually geniculate, arising from near the base to near midlength; bisexual lemmas 3.5-5.2 mm, pubescent towards the bifid apices; anthers 1.5-2.7 mm. 2n = 56, 58, 63, 66, 72.

Distribution

Maine, N.H., Alta., B.C., Greenland, Man., Nfld. And Labr., N.W.T., Nunavut, Ont., Que., Yukon, N.Y., Alaska, Vt., Mont.

Discussion

Anthoxanthum monticola is circumpolar, usually growing above or north of the tree line, occasionally in open forests. It occurs sporadically on well-drained, weakly acidic to neutral sand, gravel, and rocky barrens in most of arctic North America; it is not common to the south, even at high elevations. It is facultatively apomictic, but slow to set seed. Revegetation is best accomplished vegetatively. It is listed as threatened or endangered in several parts of its range. There are two subspecies in the Flora region.

References

None.

Key

1 Awns of the upper staminate florets 5-10.5 mm long, attached from near the base to about midlength; awn usually strongly geniculate, the lower portion usually twisted, with 2-4 gyres Anthoxanthum monticola subsp. alpinum
1 Awns of the upper staminate florets 4.5-7 mm long, attached at or above midlength, not or only weakly geniculate, the lower portion not twisted or twisted with 1-2 gyres Anthoxanthum monticola subsp. monticola