Poa douglasii

Nees
Common names: Douglas' bluegrass
Endemic
Treatment appears in FNA Volume 24. Treatment on page 551.
Please click on the illustration for a higher resolution version.
Illustrator: Sandy Long

Copyright: Utah State University

Plants perennial; loosely tufted, rhizomatous and stoloniferous, rhizomes and stolons to 1 m. Basal branching mainly intravaginal, some extravaginal. 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. 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. 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. 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. 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. 2n = 28.

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.

Selected References

None.

Lower Taxa

None.

"subequal" is not a number."decumbent" is not a number.

... more about "Poa douglasii"
membranous +  and scarious +
hispidulous +  and scabrous +
5 cm50 mm <br />0.05 m <br /> (?) +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
scarious-hyaline +
glabrous +, puberulent +  and long-villous +
Robert J. Soreng +
1 (?) +  and 3 (?) +
straight +
basal +  and terminal +
keeled +  and rounded +
strigose +  and glabrous +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
glabrous +  and hispidulous +
compressed +  and terete +
swelling +
not evident +
involute +, folded +  and flat +
thin;thick +
hispidulous +
terete +  and weakly angled +
webbed +  and glabrous +
compressed +  and terete +
folded +  and flat +
thick;1mm;2mm +
Douglas' bluegrass +
unbranched +  and hollow +
10 cm100 mm <br />0.1 m <br /> (30 cm300 mm <br />0.3 m <br />) +
ascending +  and erect +
compressed +  and terete +
7 cm70 mm <br />0.07 m <br /> (70 cm700 mm <br />0.7 m <br />) +
not woody +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
3 +  and 6 +
compressed +
reduced +
2mm +  and 10mm +
1-3(5)-veined +
shorter or longer +
subtending +
keeled +  and lanceolate +
subequal +
distributed +
uncinate +
0.1 cm1 mm <br />0.001 m <br /> (?) +
0 +  and 1/6 +
Oval (?) +  and Round (?) +
0 cm0 mm <br />0 m <br /> (30 cm300 mm <br />0.3 m <br />) +
hispidulous +, glabrous +, scabrous +  and smooth +
milky white +  and slightly greenish +
glabrous +, puberulent +  and long-villous +
hairy +  and glabrous +
keeled +  and lanceolate +
0.5 cm5 mm <br />0.005 m <br /> (0.75 cm7.5 mm <br />0.0075 m <br />) +
membranous +
erose +  and entire +
colorless +  and milky white +
truncate +  and obtuse +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
membranous +
inconspicuous +
lobed +  and lanceolate +
milky white +  and slightly greenish +
glabrous +, puberulent +  and long-villous +
concealed +  and prominent +
0 +  and 5 +
2 +  and 1 +
well-developed +
2-keeled +
subequal +
congested +  and compact +
30 cm300 mm <br />0.3 m <br /> (?) +
1.5 cm15 mm <br />0.015 m <br /> (6 cm60 mm <br />0.06 m <br />) +
dry +  and fleshy +
glabrous +, smooth or +  and sparsely moderately retrorsely scabrous +
rhizomatous +  and stoloniferous +
not bulbiferous +
compressed +
0.7 cm7 mm <br />0.007 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
extravaginal +, intravaginal +  and basal +
2 (?) +  and 3 (?) +
Gramineae +
Poa douglasii +
Poa subsect. Madropoa +
species +
membranous +
0.4 cm4 mm <br />0.004 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
parallel +  and converging +
aquatic +  and terrestrial +