Poa unilateralis

Plants perennial; frequently glaucous; densely tufted, not stoloniferous, not rhizomatous. Basal branching all or mainly intravaginal. Culms 5-40 cm, erect or ascending, frequently decumbent, terete, with 0-2 exserted nodes. Sheaths closed for 1/10(1/5) their length, terete, smooth, glabrous, bases of basal sheaths glabrous, distal sheath lengths 1-4 times widths; ligules 2-6 mm, smooth or sparsely scabrous, obtuse to acute; innovation blades usually 1-1.5 mm wide, thin, soon withering, and distinctly narrower than the cauline blades, infrequently wider, flat, and a bit fleshy as in the cauline blades, or involute; cauline blades gradually reduced in length distally, 2-5 mm wide, flat or folded, soft, thin and soon withering or moderately thick and somewhat fleshy and retaining their form, smooth, apices narrowly to broadly prow-shaped. Panicles 3-7 cm, erect, nearly cylindrical, contracted, congested, with (20)30-80(120) spikelets; nodes with 3-7 branches; branches 0.5-1.5(4.5) cm, erect, usually angled, infrequently terete or sulcate, angles usually moderately to densely scabrous, infrequently smooth with dense papillae and weak-angled, with 2-10 spikelets in the proximal 2/3; pedicels shorter than the spikelets. Spikelets 4.5-7 mm, lengths to 3.5 times widths, lanceolate to narrowly ovate, drab; florets 3-5; rachilla internodes usually shorter than 1 mm, smooth. Glumes lanceolate, slightly unequal, distinctly keeled, keels papillate or scabrous; lower glumes 3-veined; calluses glabrous or with a crown of hairs, hairs 0.1-0.2 mm; lemmas 3-4.5 mm, lanceolate, distinctly keeled, glabrous or the keels and marginal veins short-villous to midlength, intercostal regions sparsely puberulent near the base, margins glabrous, apices acute; palea keels scabrous, sometimes softly puberulent at midlength; anthers 1.5-3 mm. 2n = 42, 84.

Distribution

• Generated Map
• Legacy Map

Calif., Oreg., Wash.

Discussion

Poa unilateralis grows on grassy bluffs and cliffs near the Pacific coast of North America, from Washington to California.

Selected References

None.

Lower Taxa

Poa unilateralis subsp. pachypholis, Poa unilateralis subsp. unilateralis

Key

1	Lemmas villous on the keels and marginal veins for more than 1/3 the length of the lemmas; blades usually involute, the cauline and innovation blades similar	Poa unilateralis subsp. pachypholis
1	Lemmas glabrous or the keels and marginal veins villous or puberulent for less than 1/5 the length of the lemmas; blades flat or folded, the cauline blades sometimes wider and thicker than the innovation blades	Poa unilateralis subsp. unilateralis