Poa douglasii |
Poa marcida |
|
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Douglas' bluegrass, sand dune blue grass |
weeping bluegrass, withered blue grass |
|
Habit | Plants perennial; loosely tufted, rhizomatous and stoloniferous, rhizomes and stolons to 1 m. | Plants perennial; not rhizomatous, not stoloniferous, sometimes shortly rhizomatous, loosely to densely tufted. |
Culms | (5)10-30 cm tall, 1.2-1.5 mm thick, bases decumbent, terete or weakly compressed, hispidulous beneath the panicles; nodes terete, 0(1) exserted. |
20-80 cm. |
Sheaths | closed for about 1/2 their length, terete, smooth or sparsely to moderately retrorsely scabrous near the collars, glabrous, bases of basal sheaths glabrous, distal sheath lengths 0.9-3.5 times blade lengths; collars sparsely to moderately retrorsely scabrous, glabrous; ligules 1-2 mm, scabrous, truncate to obtuse, ciliolate; innovation blades to 30 cm long, adaxial surfaces moderately to densely scabrous or hispidulous on and between the veins; cauline blades subequal in length, 1-2 mm wide, involute, moderately thick, moderately firm, arcuate, abaxial surfaces smooth or sparsely scabrous, adaxial surfaces moderately to densely scabrous or hispidulous on and between the veins, apices narrowly prow-shaped, flag leaf blades 1-9 cm. |
closed for at least 9/10 their length; ligules 0.5-2 mm, smooth, truncate; blades 1.5-5 mm wide, flat, lax. |
Basal branching | mainly intravaginal, some extravaginal. |
mainly pseudointravaginal. |
Panicles | 1.5-6 cm, erect, compact, ovoid, contracted, infrequently interrupted, congested, with 15-50 spikelets; nodes with 1-2 branches, internodes densely hispidulous; branches 0.5-2 cm, erect, stiff, terete to weakly angled, densely hispidulous, with 1-5 spikelets. |
6-22 cm, lax, narrowly lanceoloid, sparse; nodes with 1-3 branches; branches ascending, lax, angled, angles scabrous. |
Spikelets | 7-12 mm, lengths to 3 times widths, laterally compressed, not sexually dimorphic; florets 3-6; rachilla internodes usually shorter than 0.5 mm, smooth, glabrous. |
3.5-7 mm laterally compressed; florets (1)2(4); rachilla internodes about 1 mm, smooth, glabrous. |
Glumes | broadly lanceolate, 1/2 as long as to subequal to the adjacent lemmas, distinctly keeled; lower glumes 3-veined; upper glumes 4-4.5(7+) mm, 3-veined; calluses usually with a crown of hairs, sometimes glabrous or diffusely webbed; lemmas 5-7.5 mm, lanceolate, 5-veined, distinctly keeled, keels, marginal veins, and sometimes the lateral veins short- to long-villous or softly puberulent, rarely glabrous, lateral veins moderately prominent, intercostal regions smooth, glabrous, margins glabrous, apices acute; palea keels scabrous to pectinate-ciliate, intercostal regions glabrous; anthers vestigial (0.1-0.2 mm) or (2)2.5-3.5 (4) mm. |
distinctly keeled, keels scabrous; lower glumes 1-veined; upper glumes shorter than or subequal to the lowest lemmas; calluses webbed, webs sparse; lemmas 3.2-5 mm, narrowly lanceolate, distinctly keeled, glabrous, acuminate; palea keels scabrous, sometimes sparsely so; anthers 0.5-1.2 mm. |
2n | = 28. |
= unknown. |
Poa douglasii |
Poa marcida |
|
Distribution |
CA
|
OR; WA; BC |
Discussion | Poa douglasii is a dioecious endemic that grows on coastal sand dunes in California, a habitat that is being invaded by exotic species. It is rare north of Mendocino. Its hairy rachises distinguish P. douglasii from all other species of Poa in the Flora region. It differs from P. macrantha (see next), which occupies similar habitats, in this and in its usually longer glumes and lemmas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Poa marcida is an uncommon endemic of breaks in rich, mesic, generally old growth forests of the Pacific coast, from Vancouver Island through the western foothills of the northern Cascade Mountains to central Oregon. It differs from P. saltuensis (p. 510) in its closed sheaths and attenuate lemmas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 551. | FNA vol. 24, p. 512. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Madropoa > subsect. Madropoa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Sylvestres |
Sibling taxa | ||
Name authority | Nees | Hitchc. |
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