Poa cuspidata Nutt.
Family: Poaceae
Poa cuspidata image
Sandy Long, Illustrator  
Robert J. Soreng

Plants perennial; loosely tufted or with solitary shoots, shortly rhizomatous. Basal branching mainly extravaginal. Culms 15–60 cm, erect or the bases decumbent, not branching above the base, terete or weakly compressed; nodes terete, 0–1 exserted. Sheathsclosed for about 1/2 their length, slightly compressed, distinctly keeled, glabrous, bases of basal sheaths glabrous, distal sheath lengths 4–60 times blade lengths; collars of proximal leaves usually retrorsely scabrous or pubescent distally and about the throat; ligules 0.5–4 mm, smooth or scabrous, apices truncate to acute; innovation blades similar to the cauline blades; cauline blades 1–4 mm wide, usually flat, sometimes slightly folded, smooth or sparsely scabrous, primarily over the veins, apices broadly prow-shaped, blades steeply reduced in length distally, flag leaf blades 0.2–3(6) cm. Panicles 5–15 cm, erect or lax, pyramidal, open, sparse, with 20–80 spikelets, proximal internodes usually 3+ cm; nodes usually with 2 branches; branches (2)3–7(10) cm, spreading to reflexed, straight, angled, angles scabrous, with 2–8(10) spikelets. Spikelets 5–8 mm, lengths to 3.5 times widths, laterally compressed, not sexually dimorphic; florets 2–5; rachilla internodes smooth. Glumes narrowly lanceolate to lanceolate, distinctly keeled; lower glumes 1–3-veined; calluses webbed, hairs over 1/3 the lemma length; lemmas 3–6 mm, lanceolate, distinctly keeled, keels and marginal veins sparsely short- to long-villous, lateral veins moderately prominent, intercostal regions glabrous or the upper florets in the spikelets softly puberulent, margins glabrous, apices acute; palea keels scabrous, softly puberulent at midlength; anthers vestigial (0.1–0.2 mm) or 2–3.5 mm. 2n = 28.

Poa cuspidata is a common species of forest openings in the Appalachian Mountains. It is an eastern counterpart of P. arnowiaeP. tracyi, and P. nervosa. Like those species, it is sequentially gynomonoecious.