Poa reflexa |
Poa pringlei |
|
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nodding bluegrass |
Pringle's blue grass |
|
Habit | Plants perennial, short-lived; densely tufted, tuft bases narrow or not, not stoloniferous, not rhizomatous. | Plants perennial; densely tufted, not stoloniferous, not rhizomatous. |
Culms | 10-60 cm. |
5-35 cm tall, 0.5-0.9 mm thick, erect or the bases decumbent, with 0(1) exserted nodes. |
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 1/7 - 1/3 their length, terete, smooth or sparsely scabrous, glabrous, bases of basal sheaths glabrous, distal sheath lengths 2-4 times blade lengths; collar margins smooth or scabrous to hispidulous; ligules of cauline leaves 1-6 mm, colorless, translucent, smooth or scabrous, truncate to acute, ligules of the innovations 1-2.5 mm; innovation blades similar to the cauline blades, 1.5-3 mm wide, involute, thick, frequently somewhat arcuate, abaxial surfaces smooth, adaxial surfaces densely scabrous or hispidulous; cauline blades becoming only slightly shorter distally, 1.5-3 mm wide, involute, moderately thick, soft to moderately firm, abaxial surfaces smooth, apices narrowly prow-shaped. |
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. |
1-6 cm, erect, narrowly lanceoloid to ovoid, moderately congested, with 6-20(25) spikelets; nodes with 1-2 branches; branches 0.5-1.5(2) cm, erect, moderately stout, terete or weakly angled, angles smooth to fairly densely scabrous, with 1-3 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. |
6-8(12) mm, lengths to 3.5 times widths, broadly lanceolate, laterally compressed, not sexually dimorphic, lustrous; florets 2-5; rachilla internodes smooth. |
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. |
subequal, isomorphic, lanceolate to broadly lanceolate, thin, lustrous, distinctly keeled, keels smooth or sparsely scabrous; lower glumes shorter than the adjacent lemmas, 3-veined; calluses glabrous; lemmas 5-8 mm, lanceolate, distinctly keeled, thinly membranous, smooth or sparsely finely scabrous, glabrous, lateral veins moderately prominent, margins glabrous, apices acute; palea keels coarsely scabrous; anthers vestigial (0.1-0.2 mm) or 2-4 mm. |
2n | = 28. |
= unknown. |
Poa reflexa |
Poa pringlei |
|
Distribution |
AZ; CO; ID; MT; NM; NV; OR; UT; WY
|
CA; NV; OR |
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 pringlei grows on rocky subalpine and alpine slopes in Oregon and California. Sexual populations, with approximately equal numbers of pistillate and staminate plants, are confined to the Klamath-Siskiyou region; Sierra Nevada populations are pistillate and apomictic. Hitchock (1951) included P. cusickii subsp. pallida (p. 560), P. keckii (p. 584), and P. suksdorfii (p. 584) in P. pringlei; the illustration (Fig. 171) is of P. cuscikii subsp. pallida. Hybrids otPoa pringlei with P. cusickii (p. 560) have been found on Mount Shasta, California, Mount Rose, Nevada, and near Crater Lake, Oregon. Poa pringlei differs from P. curtifolia (p. 589) in being dioecious and in having blades that are involute, soft to moderately firm, and abaxially pubescent. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 538. | FNA vol. 24, p. 564. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Homalopoa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Madropoa > subsect. Epiles |
Sibling taxa | ||
Name authority | Vasey & Scribn. | Scribn. |
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