Poa abbreviata
Plants perennial; not or scarcely glaucous; densely tufted, not stoloniferous, not rhizomatous. Basal branching all or mainly intravaginal. Culms 5-15(20) cm, slender, leafless above the basal tuft. Sheaths closed for 1/10 – 1/4 their length, terete; ligules 0.4-5.5 mm, milky white to hyaline, smooth or scabrous, apices truncate to acute; blades 0.8-1.5(2) mm wide, involute, moderately thick, soft, apices narrowly prow-shaped. Panicles 1.5-5 cm, erect, lanceoloid to ovoid, contracted, congested; nodes with 1-3 branches; branches to 1.5 cm, erect, slender, terete, sulcate or angled, smooth or the angles sparsely scabrous; pedicels usually shorter than the spikelets. Spikelets 4-6.5 mm, laterally compressed, rarely bulbiferous, frequently strongly anthocyanic; florets 2-5, rarely bulb-forming; rachilla internodes usually shorter than 1 mm, smooth or scabrous. Glumes subequal to slightly longer than the adjacent lemmas, lanceolate to broadly lanceolate, distinctly keeled, keels smooth; lower glumes (1)3-veined, lateral veins often faint and short; upper glumes exceeding or exceeded by the upper florets; calluses glabrous or webbed; lemmas 3-4.6 mm, lanceolate to broadly lanceolate, distinctly keeled, thin, keels and marginal veins usually short- to long-villous, hairs extending along 3/4 - 5/6 of the keel, infrequently glabrous, intercostal regions glabrous or softly puberulent to short-villous, apices acute; palea keels scabrous, often short-villous to softly puberulent at midlength, sometimes glabrous; anthers 0.2-1.2(1.8) mm. 2n = 42.
Distribution
Colo., Alaska, Idaho, Nev., Utah, Alta., B.C., Greenland, N.W.T., Nunavut, Yukon, Mont., Wyo., Calif., Oreg.
Discussion
Poa abbreviata is an alpine and circumarctic species which has two subspecies in the western Cordilleras, and one in the high arctic. It grows mainly on frost scars and mesic rocky slopes, usually on open ground. In rare cases where the lemmas and calluses of P. abbreviata ate glabrous, it can be confused with P. lettermanii (p. 580), but that species has shorter spikelets and glumes that are longer than the adjacent florets.
Selected References
None.
Lower Taxa
Key
| 1 | Lemmas glabrous; calluses webbed | Poa abbreviata subsp. marshii |
| 1 | Lemmas usually with hairs over the veins; calluses glabrous or webbed, rarely both the lemmas and calluses glabrous. | > 2 |
| 2 | Anthers 0.2-0.8 mm long; lemma intercostal regions hairy | Poa abbreviata subsp. abbreviata |
| 2 | Anthers 0.6-1.2(1.8) mm long; lemma intercostal regions glabrous or hairy | Poa abbreviata subsp. pattersonii |