Poa laxiflora

Buckley
Common names: Lax-flower bluegrass
Endemic
Treatment appears in FNA Volume 24. Treatment on page 538.
Please click on the illustration for a higher resolution version.
Illustrator: Sandy Long

Copyright: Utah State University

Plants perennial; green throughout; loosely tufted or with solitary shoots, long-rhizomatous. Basal branching extravaginal. Culms 50-120 cm. Sheaths closed for 1/2 - 3/4 their length, usually sparsely to moderately retrorsely scabrous, margins not ciliate; ligules 2-3.5 mm, smooth or sparsely scabrous, obtuse to acute; blades 3-8 mm wide, flat, lax, apices narrowly prow-shaped. Panicles 14-30 cm, open, sparse, with 1-3 (4) branches per node; branches (5.5) 8-12 (15) cm, widely spreading, fairly straight, angled, angles sparsely to moderately scabrous, with 3-13 spikelets. Spikelets 4-8 mm, laterally compressed, rarely bulbiferous; florets 2-4, usually normal, rarely bulb-forming; rachilla internodes about 1 mm, smooth, glabrous. Glumes distinctly keeled, keels scabrous; lower glumes lanceolate, 1-3-veined; upper glumes shorter than or subequal to the lowest lemmas; calluses webbed; lemmas 3.2-6 mm, lanceolate, distinctly keeled, smooth or sparsely finely scabrous, keels and marginal veins long-villous, keels hairy to 2/3 – 3/4 their length, marginal veins sparsely hairy, lateral-veins moderately prominent, usually glabrous, rarely sparsely softly puberulent, intercostal regions glabrous, apices acute; paleas scabrous, glabrous over the keels; anthers 0.5-1.1 mm. 2n = ca. 98.

Distribution

Alaska, Oreg., Wash., B.C.

Discussion

Poa laxiflora is restricted to mesic, old growth, mixed conifer forests of the Pacific coast, from Alaska south through the western foothills of the northern Cascades to Oregon. It is not a common species. A bulbiferous specimen was collected in the Queen Charlotte Islands.

Inclusion of Poa laxiflora in Poa sect. Homalopoa is tentative; it may belong to sect. Sylvestres.

Selected References

None.

Lower Taxa

None.

No values specified."decumbent" is not a number.

... more about "Poa laxiflora"
membranous +  and scarious +
puberulent +, hispidulous +, hairy +  and glabrous +
1.8 cm18 mm <br />0.018 m <br /> (?) +
1.5mm +  and 3mm +
3 +  and 1 +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
scarious-hyaline +
acute +  and prow--shaped +
Robert J. Soreng +
Buckley +
1 (?) +  and 3 (?) +
straight +
basal +  and terminal +
keeled +  and rounded +
strigose +  and glabrous +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
not evident +
involute +, folded +  and flat +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
5.5 cm55 mm <br />0.055 m <br /> (?) +
hispidulous +, glabrous +, smooth or +  and sparsely densely scabrous +
8 cm80 mm <br />0.08 m <br /> (12 cm120 mm <br />0.12 m <br />) +
compressed +  and terete +
folded +  and flat +
Lax-flower bluegrass +
unbranched +  and hollow +
ascending +  and erect +
compressed +  and terete +
50 cm500 mm <br />0.5 m <br /> (120 cm1,200 mm <br />1.2 m <br />) +
not woody +
Alaska +, Oreg. +, Wash. +  and B.C. +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
2 +  and 4 +
compressed +
reduced +
1-3(5)-veined +
shorter or longer +
subtending +
unequal +  and subequal +
distributed +
uncinate +
0.1 cm1 mm <br />0.001 m <br /> (?) +
0 +  and 1/6 +
Oval (?) +  and Round (?) +
milky white +  and slightly greenish +
hairy +  and long-villous +
puberulent +  and glabrous +
5(7-11)-veined +
hairy +  and glabrous +
keeled +  and lanceolate +
0.32 cm3.2 mm <br />0.0032 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
membranous +
erose +  and entire +
milky white +
ciliolate +  and smooth +
obtuse +  and acute +
0.2 cm2 mm <br />0.002 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
membranous +
inconspicuous +
lobed +  and lanceolate +
milky white +
glabrous +, scabrous +  and smooth +
hairy +  and long-villous +
concealed +  and prominent +
0 +  and 5 +
compressed +  and terete +
2 +  and 1 +
well-developed +
2-keeled +
subequal +
1 cm10 mm <br />0.01 m <br /> (?) +
nodding +  and erect +
spikelike +
14 cm140 mm <br />0.14 m <br /> (30 cm300 mm <br />0.3 m <br />) +
dry +  and fleshy +
terete +  and distinctly compressed +
long-rhizomatous +
3 +  and 13 +
compressed +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
1 +  and 3 +
simple +  and compound +
2 (?) +  and 3 (?) +
Gramineae +
Poa laxiflora +
Poa sect. Homalopoa +
species +
membranous +
parallel +  and converging +
with solitary shoots +  and tufted +
aquatic +  and terrestrial +