Poa reflexa |
Poa keckii |
|
---|---|---|
nodding bluegrass |
Keck's blue grass |
|
Habit | Plants perennial, short-lived; densely tufted, tuft bases narrow or not, not stoloniferous, not rhizomatous. | Plants perennial; not glaucous; densely tufted, not stoloniferous, not rhizomatous. |
Culms | 10-60 cm. |
2-10(18) cm, erect to spreading; nodes terete, none 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 1/10 – 1/5 their length, terete, smooth, glabrous, bases of basal sheaths glabrous, distal sheath lengths 1.5-7 times blade lengths; collars smooth, glabrous; ligules 1-3 mm, milky white, smooth or sparsely scabrous, apices obtuse to acute, ligules of upper innovation leaves shorter than 3 mm; innovation blades similar to the cauline blades; cauline blades 1-3.5(4.5) cm long, 0.9-1.8 mm wide, folded, moderately thick, soft, smooth, glabrous, adaxial surfaces infrequently sparsely scabrous, usually with papillae on the long cells (at 100x), apices narrowly prow-shaped, flag leaf blades folded, 1-1.8 mm wide, abaxial surfaces with 7-15 closely spaced, slightly protruding ribs. |
Basal branching | mixed intra- and extravaginal. |
all or mainly 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. |
1-4(6) cm, erect, ovoid to lanceoloid, contracted, congested, with 9-40 spikelets; nodes with 1-3 branches; branches 0.5-1.5 cm, erect, fairly straight, sulcate or angled, angles sparsely to densely scabrous, with 1-7 spikelets; pedicels shorter than the 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. |
3.5-6 mm long, lengths to 3.5(3.8) times widths, lanceolate, laterally compressed, fairly strongly anthocyanic, not glaucous; florets 2-3; rachilla internodes terete, to 1.5 mm, smooth, sometimes sparsely hispidulous. |
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. |
lanceolate, smooth, distinctly keeled, keels sparsely scabrous; lower glumes shorter than to equaling the lowest lemmas, 3-veined; upper glumes frequently exceeding the lowest lemmas, exceeded by the upper lemmas; calluses glabrous; lemmas 3-4.9 mm, lanceolate, distinctly keeled, thin, smooth or finely scabrous, glabrous or the keels and marginal veins sparsely puberulent proximally, lateral veins obscure, margins glabrous, apices acute; palea keels scabrous; anthers 0.6-1.3(1.8) mm. |
2n | = 28. |
= unknown. |
Poa reflexa |
Poa keckii |
|
Distribution |
AZ; CO; ID; MT; NM; NV; OR; UT; WY
|
CA |
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 keckii is endemic to high alpine frost scars and ledges, usually on open ground, in the Sierra Nevada and adjacent Sweetwater and White mountains of California. It is very similar to Poa suksdorfii (see next), but is consistently distinct in its details. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 538. | FNA vol. 24, p. 584. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Homalopoa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Abbreviatae |
Sibling taxa | ||
Name authority | Vasey & Scribn. | Soreng |
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