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Douglas' bluegrass, sand dune blue grass

supine bluegrass

Habit Plants perennial; loosely tufted, rhizomatous and stoloniferous, rhizomes and stolons to 1 m. Plants perennial; stoloniferous, loosely 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.

8-12(20) cm, slender, bases decumbent, terete or weakly compressed;

nodes terete, 1 exserted.

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 1/4-1/3 their length, terete, smooth, glabrous, bases of basal sheaths glabrous, distal sheath lengths 2-4 times blade lengths;

collars smooth, glabrous;

ligules 0.6-1 mm, smooth, glabrous, truncate;

blades 2-3 mm wide, flat, thin, soft, smooth, apices broadly prow-shaped, cauline blades subequal.

Basal branching

mainly intravaginal, some extravaginal.

intravaginal.

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.

2.5-5 cm, lengths 1-2 times widths, erect, loosely contracted or open, ovoid to pyramidal, sparse, with 10-25(30) spikelets and 1-2 branches per node;

branches 1-3 cm, spreading to reflexed, straight, terete, smooth or sparsely scabrous, with 2-5(8) spikelets.

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.

4-6 mm, laterally compressed;

florets 3-7;

rachilla internodes smooth, glabrous, more or less concealed, distal internode less than 1/2 the length of the distal lemma.

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 smooth;

lower glumes 1-veined;

calluses glabrous;

lemmas 1.7-4 mm, lanceolate, distinctly keeled, smooth throughout, proximal lemmas glabrous throughout or the keels and marginal veins sparsely short-villous, distal lemmas glabrous or the keels and marginal veins short-villous to near the apices, lateral veins moderately prominent, intercostal regions glabrous, margins smooth, glabrous, apices obtuse to acute;

palea keels smooth, sometimes sparsely softly puberulent to short-villous;

anthers (1.25)1.5-2.5 mm, cylindrical prior to dehiscence, those of the upper 1-2 florets commonly vestigial.

2n

= 28.

= 14.

Poa douglasii

Poa supina

Distribution
from FNA
CA
[WildflowerSearch map]
[BONAP county map]
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 supina is native to boreal to alpine regions of Eurasia. Beginning in the 1990s, the cultivar 'Supernova' has been introduced for seeding in wet to moist, cool, shady areas subject to heavy traffic. It has been tested in both Canada and the United States, and is expected to gradually escape cultivation, probably becoming established throughout the cool-temperate portion of the Flora region. Its current distribution is not known. Poa supina differs from P. annua (p. 519), of which is thought to be one of the parents, in having longer anthers and a more stoloniferous habit, as well as in being diploid. It is gynomonoecious.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 24, p. 551. FNA vol. 24, p. 521.
Parent taxa Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Madropoa > subsect. Madropoa Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Micrantherae
Sibling taxa
P. abbreviata, P. alpina, P. alsodes, P. ammophila, P. annua, P. arachnifera, P. arctica, P. arida, P. arnowiae, P. atropurpurea, P. autumnalis, P. bigelovii, P. bolanderi, P. bulbosa, P. chaixii, P. chambersii, P. chapmaniana, P. compressa, P. confinis, P. curtifolia, P. cusickii, P. cuspidata, P. diaboli, P. eminens, P. fendleriana, P. glauca, P. hartzii, P. howellii, P. infirma, P. interior, P. keckii, P. kelloggii, P. laxa, P. laxa × glauca, P. laxiflora, P. leibergii, P. leptocoma, P. lettermanii, P. macrantha, P. macrocalyx, P. marcida, P. napensis, P. nemoralis, P. nervosa, P. occidentalis, P. paludigena, P. palustris, P. paucispicula, P. piperi, P. porsildii, P. pratensis, P. pringlei, P. pseudoabbreviata, P. reflexa, P. rhizomata, P. saltuensis, P. secunda, P. sierrae, P. stebbinsii, P. stenantha, P. strictiramea, P. sublanata, P. suksdorfii, P. supina, P. sylvestris, P. tenerrima, P. tracyi, P. trivialis, P. unilateralis, P. wheeleri, P. wolfii, P. ×gaspensis, P. ×limosa, P. ×nematophylla
P. abbreviata, P. alpina, P. alsodes, P. ammophila, P. annua, P. arachnifera, P. arctica, P. arida, P. arnowiae, P. atropurpurea, P. autumnalis, P. bigelovii, P. bolanderi, P. bulbosa, P. chaixii, P. chambersii, P. chapmaniana, P. compressa, P. confinis, P. curtifolia, P. cusickii, P. cuspidata, P. diaboli, P. douglasii, P. eminens, P. fendleriana, P. glauca, P. hartzii, P. howellii, P. infirma, P. interior, P. keckii, P. kelloggii, P. laxa, P. laxa × glauca, P. laxiflora, P. leibergii, P. leptocoma, P. lettermanii, P. macrantha, P. macrocalyx, P. marcida, P. napensis, P. nemoralis, P. nervosa, P. occidentalis, P. paludigena, P. palustris, P. paucispicula, P. piperi, P. porsildii, P. pratensis, P. pringlei, P. pseudoabbreviata, P. reflexa, P. rhizomata, P. saltuensis, P. secunda, P. sierrae, P. stebbinsii, P. stenantha, P. strictiramea, P. sublanata, P. suksdorfii, P. sylvestris, P. tenerrima, P. tracyi, P. trivialis, P. unilateralis, P. wheeleri, P. wolfii, P. ×gaspensis, P. ×limosa, P. ×nematophylla
Name authority Nees Schrad.
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