Difference between revisions of "Trisetum melicoides"

Revision as of 22:16, 16 December 2019

Plants perennial, with both fertile and sterile shoots; cespitose. Culms (20)40-80(100) cm, erect, smooth or scabridulous. Leaves concentrated below midlength on the culms; sheaths glabrous or pilose; ligules 1.5-3.5 mm, rounded or truncate; blades 10-20+ cm long, 2-9 mm wide, flat, lax. Panicles 8-20 cm long, usually 2-4 cm wide, lax, nodding, silvery-green or tan; lower branches to 5 cm, ascending, naked below, the spikelets imbricate distally. Spikelets 5-7(9) mm, pedicellate, lance-ovate, with 2(4) florets; rachilla internodes and hairs 1.3-2 mm. Glumes unequal, widest at or below the middle; lower glumes 4-5.5 mm; upper glumes 5-7 mm long, nearly as long as the florets, wider than the lower glumes; callus hairs 1.5-2 mm; lemmas 5-6 mm, smooth or scabridulous, apices usually minutely bifid, sometimes entire, unawned or awned. awns to 2 mm, arising just below and rarely exceeding the apices; paleas shorter than the lemmas; anthers 0.6-0.8 mm. Caryopses about 3 mm, sparsely pubescent distally. 2n = 14.

Maine, N.H., Vt., Mich., Wis., N.Y., N.B., Nfld. And Labr. (Labr.), N.S., Ont., Que.

Discussion

Trisetum melicoides is a native species that grows on moist, cool stream banks, gravelly shores, shaded rock ledges (especially calcareous ones), and in damp woods. It grows only in southeastern Canada and the northeastern United States. It is listed as endangered in Wisconsin, New York, and Maine. Plants with pilose sheaths have been called T. melicoides var. majus (A. Gray) Hitchc, but the trait varies within populations.

Selected References

None.

Lower Taxa