Poa reflexa |
Poa supina |
|
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nodding bluegrass |
supine bluegrass |
|
Habit | Plants perennial, short-lived; densely tufted, tuft bases narrow or not, not stoloniferous, not rhizomatous. | Plants perennial; stoloniferous, loosely tufted. |
Culms | 10-60 cm. |
8-12(20) cm, slender, bases decumbent, terete or weakly compressed; nodes terete, 1 exserted. |
Sheaths | closed for 1/3 – 2/3 their length, terete, smooth; ligules 1.5-3.5 mm, smooth or sparsely scabrous; blades 1.5-4 mm wide, flat, thin, soft, apices broadly prow-shaped. |
closed for 1/4-1/3 their length, terete, smooth, glabrous, bases of basal sheaths glabrous, distal sheath lengths 2-4 times blade lengths; collars smooth, glabrous; ligules 0.6-1 mm, smooth, glabrous, truncate; blades 2-3 mm wide, flat, thin, soft, smooth, apices broadly prow-shaped, cauline blades subequal. |
Basal branching | mixed intra- and extravaginal. |
intravaginal. |
Panicles | 4-15 cm, nodding, open, with numerous spikelets and 1-2 branches per node; branches (2)3-7 cm, spreading to reflexed, lower branches usually reflexed, flexuous, usually terete, smooth or sparsely scabrous, with (3)6-18 spikelets. |
2.5-5 cm, lengths 1-2 times widths, erect, loosely contracted or open, ovoid to pyramidal, sparse, with 10-25(30) spikelets and 1-2 branches per node; branches 1-3 cm, spreading to reflexed, straight, terete, smooth or sparsely scabrous, with 2-5(8) spikelets. |
Spikelets | 4-6 mm, lanceolate to broadly lanceolate, usually partly to wholly purplish, with 3-5 florets; rachilla internodes shorter than 1 mm, smooth. |
4-6 mm, laterally compressed; florets 3-7; rachilla internodes smooth, glabrous, more or less concealed, distal internode less than 1/2 the length of the distal lemma. |
Glumes | narrowly to broadly lanceolate, distinctly keeled, keels smooth or nearly so; lower glumes 1-veined; upper glumes shorter than or subequal to the lowest lemmas; calluses webbed; lemmas 2-3.5 mm, lanceolate, partly purple to fairly strongly purple, distinctly keeled, keels and marginal veins short- to long-villous, keels hairy for 2h-ls their length, lateral veins usually sparsely softly puberulent at least on 1 side, lateral veins obscure to moderately prominent, intercostal regions smooth, minutely bumpy, glabrous, apices acute, slightly bronze-colored or not; palea keels scabrous, usually softly puberulent at midlength; anthers 0.6-1 mm. |
distinctly keeled, keels smooth; lower glumes 1-veined; calluses glabrous; lemmas 1.7-4 mm, lanceolate, distinctly keeled, smooth throughout, proximal lemmas glabrous throughout or the keels and marginal veins sparsely short-villous, distal lemmas glabrous or the keels and marginal veins short-villous to near the apices, lateral veins moderately prominent, intercostal regions glabrous, margins smooth, glabrous, apices obtuse to acute; palea keels smooth, sometimes sparsely softly puberulent to short-villous; anthers (1.25)1.5-2.5 mm, cylindrical prior to dehiscence, those of the upper 1-2 florets commonly vestigial. |
2n | = 28. |
= 14. |
Poa reflexa |
Poa supina |
|
Distribution |
AZ; CO; ID; MT; NM; NV; OR; UT; WY
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Discussion | Poa reflexa grows in subalpine forests, meadows, and low alpine habitats, primarily in the central and southern Rocky Mountains. It usually grows on drier and more disturbed sites, and appears shorter-lived, than the frequently sympatric or parapatric P. leptocoma (p. 573), from which it differs in usually having hairs on the palea keels and lateral veins of the lemmas, and smooth panicle branches. In addition, P. reflexa is tetraploid, whereas P. leptocoma is hexaploid. Poa reflexa may resemble small plants of P. occidentalis (see previous) in habit. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Poa supina is native to boreal to alpine regions of Eurasia. Beginning in the 1990s, the cultivar 'Supernova' has been introduced for seeding in wet to moist, cool, shady areas subject to heavy traffic. It has been tested in both Canada and the United States, and is expected to gradually escape cultivation, probably becoming established throughout the cool-temperate portion of the Flora region. Its current distribution is not known. Poa supina differs from P. annua (p. 519), of which is thought to be one of the parents, in having longer anthers and a more stoloniferous habit, as well as in being diploid. It is gynomonoecious. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 538. | FNA vol. 24, p. 521. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Homalopoa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Micrantherae |
Sibling taxa | ||
Name authority | Vasey & Scribn. | Schrad. |
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