Poa macrantha |
Poa pringlei |
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dune bluegrass, large flower sand dune blue grass, sand-dune blue grass, seashore blue grass |
Pringle's blue grass |
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Habit | Plants perennial; loosely tufted, rhizomatous and stoloniferous, rhizomes and stolons to 4 m, stout, robust. | Plants perennial; densely tufted, not stoloniferous, not rhizomatous. |
Culms | (7)15-60 cm tall, 1.5-2 mm thick, bases decumbent, terete or weakly compressed, smooth or moderately scabrous below the panicles; nodes terete, 0(1) exserted. |
5-35 cm tall, 0.5-0.9 mm thick, erect or the bases decumbent, with 0(1) exserted nodes. |
Sheaths | closed for about 1/2 their length, terete, glabrous or sparsely retrorsely scabrous, bases of basal sheaths glabrous, distal sheath lengths 1.7-4(6) times blade lengths; collars smooth, glabrous; ligules 1-5 mm, scabrous, truncate to acute, ciliolate; innovation blades to 30 cm, moderately to densely scabrous or hispidulous on and between the veins; cauline blades subequal in length, 2-4 mm wide, involute, thick, somewhat arcuate, firm, abaxial surfaces smooth or moderately to densely scabrous or hispidulous on and between the veins, apices narrowly prow-shaped, flag leaf blades 1-10 cm. |
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 | mostly intravaginal, some extravaginal. |
intravaginal. |
Panicles | 3-15 cm, erect, ovoid to lanceolate, contracted, often interrupted, congested, with 15-80 spikelets, rachises glabrous, smooth to moderately scabrous; nodes with 1-2 branches; branches 1-6 cm, erect, stiff, terete to weakly angled, smooth or sparsely to moderately scabrous, with 3-17 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 | 9-17 mm, lengths to 3 times widths, laterally compressed, not sexually dimorphic; florets 3-6(10); rachilla internodes smooth, usually hairy, hairs 0.3-0.4+ mm, rarely glabrous. |
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 | broadly lanceolate, subequal to the adjacent lemmas, distinctly keeled, keels sparsely scabrous near the apices; lower glumes 3-veined; upper glumes usually 7+ mm, 3-5-veined; calluses usually with a crown of hairs, sometimes glabrous or diffusely webbed; lemmas (6)7.5-11 mm, lanceolate, 5-7(11)-veined, distinctly keeled, keels and marginal veins, and sometimes the lateral veins, short-villous to softly puberulent, intercostal regions smooth or scabrous, glabrous or softly puberulent, margins glabrous, apices acute; palea keels scabrous, intercostal regions glabrous; anthers vestigial (0.1-0.2 mm) or (2)3-4(5) 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 macrantha |
Poa pringlei |
|
Distribution |
AK; CA; OR; WA; BC
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CA; NV; OR |
Discussion | Poa macrantha is a dioecious coastal sand dune species that grows from southern Alaska to northern California. It competes better than P. douglasii (see previous) with the invasion of its habitat by Ammophila and other exotic species. It used to be treated as a subspecies of P. douglasii; a few intermediates with that species have been found around the mouth of Little River, California. Although clearly related, the two species are reasonably divergent in a number of characters. Poa macrantha is readily distinguished from P. douglasii by its glabrous rachises and usually longer glumes and lemmas. (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. 551. | FNA vol. 24, p. 564. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Madropoa > subsect. Madropoa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Madropoa > subsect. Epiles |
Sibling taxa | ||
Synonyms | P. douglasii subsp. macrantha | |
Name authority | Vasey | Scribn. |
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