Poa reflexa |
Poa confinis |
|
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nodding bluegrass |
beach blue grass, coastal bluegrass, coastline blue grass |
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Habit | Plants perennial, short-lived; densely tufted, tuft bases narrow or not, not stoloniferous, not rhizomatous. | Plants perennial; densely to loosely tufted, rhizomatous and stoloniferous, rhizomes and stolons to 1 m, slender. |
Culms | 10-60 cm. |
7-30 (35) cm tall, 0.4-0.9 mm thick, slender, erect or the bases decumbent, terete or weakly compressed; nodes terete, 0-1 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 1/3-2/3 their length, terete, smooth, glabrous, bases of basal sheaths glabrous, distal sheath lengths (1)1.4-4.5 times blade lengths; collars smooth, glabrous; ligules 0.5-1.5(2.2) mm, scabrous, truncate to acute; innovation blades adaxially moderately to densely scabrous or hispidulous on and between the veins; cauline blades slightly reduced in length distally, 0.5-1(1.5) mm wide, involute, thin to moderately thick, usually filiform, soft, abaxial surfaces smooth, adaxial surfaces sparsely scabrous on and between the veins, apices narrowly prow-shaped, flag leaf blades (0.5)1-5 cm. |
Basal branching | mixed intra- and extravaginal. |
mainly intravaginal, some extravaginal. |
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. |
1-5(7) cm, erect, ovoid, fairly tightly to loosely contracted, congested or moderately congested, with fewer than 50 spikelets; nodes with 1-2 branches; branches 0.5-3 cm, erect to ascending, slightly lax, terete or angled, angles sparsely to densely scabrous, with 2-12 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. |
3-6(8) mm, lengths to 3 times widths, laterally compressed, compact, not sexually dimorphic; florets 2-5; rachilla internodes 0.8-1.1 mm, usually not readily visible from the sides, glabrous or sparsely puberulent. |
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. |
slightly unequal, distinctly keeled, keels smooth or scabrous; lower glumes 2-4 mm, 1-3-veined, about 2/3 the length of the adjacent lemmas; upper glumes 2.9-5 mm; calluses usually diffusely webbed, hairs 1-2 mm, infrequently glabrous; lemmas 2.5-4(4.5) mm, lanceolate, distinctly keeled, moderately to densely finely scabrous, glabrous throughout or the keels and sometimes the marginal veins sparsely puberulent proximally, margins narrowly scarious, glabrous, apices acute; paleas subequal to the lemmas, keels scabrous, intercostal regions glabrous; anthers vestigial (0.1-0.2 mm) or 1.5-2 mm. |
2n | = 28. |
= 42. |
Poa reflexa |
Poa confinis |
|
Distribution |
AZ; CO; ID; MT; NM; NV; OR; UT; WY
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CA; OR; WA; BC |
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 confinis grows on sandy beaches and forest margins of the west coast, a habitat that is being lost to invasion by exotic species and development. It is closely related to P. diaboli (see next), from which it differs by a suite of characters. The two species are ecologically and geographically distinct. Poa confinis differs from P. pratensis (p. 522) in having glabrous or sparsely hairy lemmas and diffusely webbed calluses. It is gynodioecious. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 538. | FNA vol. 24, p. 552. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Homalopoa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Madropoa > subsect. Madropoa |
Sibling taxa | ||
Name authority | Vasey & Scribn. | Vasey |
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