Poa cuspidata |
Poa strictiramea |
|
---|---|---|
early bluegrass |
Big Bend bluegrass |
|
Habit | Plants perennial; loosely tufted or with solitary shoots, shortly rhizomatous. | Plants perennial; densely tufted, not stoloniferous, not rhizomatous. |
Culms | 15-60 cm, erect or the bases decumbent, not branching above the base, terete or weakly compressed; nodes terete, 0-1 exserted. |
30-90 cm, slender to coarse. |
Sheaths | closed 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. |
closed for 1/20 – 1/10 their length, terete, scabrous, glabrous; collars smooth to scabrous; ligules 0.5-4(6) mm, scabrous, apices truncate to acute, entire or lacerate; innovation blades 15-30 cm; cauline blades 1-4 mm wide, involute or rarely flat, moderately thick and firm, both surfaces sparsely to densely antrorsely scabrous, apices narrowly prow-shaped, flag leaf blades usually longer than their sheaths. |
Basal branching | mainly extravaginal. |
intra-vaginal. |
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. |
(7)10-30 cm, erect, pyramidal, open, with 2-5 branches per node; branches 2-8(15) cm, spreading, straight, angled, angles moderately to densely scabrous, sometimes densely scabrous all over, with 10-30 spikelets. |
Spikelets | 5-8 mm, lengths to 3.5 times widths, laterally compressed, not sexually dimorphic; florets 2-5; rachilla internodes smooth. |
4-7 mm, lanceolate, laterally compressed; florets 2-5; rachilla internodes 0.8-1.5 mm, smooth or scabrous, sometimes sparsely hispidulous. |
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. |
sparsely to rarely densely scabrous; lower glumes 1-3-veined; calluses usually glabrous, rarely sparsely short-webbed; lemmas 2.5-3.5 mm, lanceolate, distinctly keeled, smooth or sparsely to densely scabrous, keels and marginal veins glabrous or softly puberulent or short- to long-villous, lateral veins moderately prominent to prominent, intercostal regions usually glabrous, infrequently sparsely softly puberulent, apices acute; palea keels scabrous; anthers aborted late in development, or 2.2-2.5 mm. |
2n | = 28. |
= 28+1, 28-29+11. |
Poa cuspidata |
Poa strictiramea |
|
Distribution |
AL; DC; DE; GA; IN; KY; LA; MD; NC; NJ; NY; OH; PA; SC; TN; VA; WV
|
TX |
Discussion | Poa cuspidata is a common species of forest openings in the Appalachian Mountains. It is an eastern counterpart of P. arnowiae (see previous), P. tracyi (p. 543), and P. nervosa (see next). Like those species, it is sequentially gynomonoecious. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Poa strictiramea grows on shady, upland mountain slopes, usually below north-facing cliffs, in and around the Chihuahuan Desert. In the United States, it is known only from the Chisos Mountains, Texas. It used to be treated as P. involuta Hitchc. Plants from the eastern part of its range, including the Chisos Mountains, commonly have short, truncate ligules, whereas westward in Mexico, plants with long, acute ligules are more common. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 545. | FNA vol. 24, p. 540. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Madropoa > subsect. Poa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Homalopoa |
Sibling taxa | ||
Synonyms | P. involuta | |
Name authority | Nutt. | Hitchc. |
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