Agrostis oregonensis

Vasey
Common names: Oregon redtop
Endemic
Treatment appears in FNA Volume 24. Treatment on page 649.
Please click on the illustration for a higher resolution version.
Illustrator: Sandy Long

Copyright: Utah State University

Plants perennial; cespitose, not rhizomatous or stoloniferous. Culms 12-75 cm, erect, with up to 5 nodes. Leaves mostly basal, basal leaves usually persistent; sheaths smooth or scabridulous, ligules 1.2-6.3 mm, usually scabridulous, sometimes smooth, truncate to rounded, lacerate-erose; blades 10-30 cm long, (1) 2-4 mm wide, flat, culm blades usually less substantial than the basal blades. Panicles 8-35 (60) cm long, (1.5) 2.5-14 cm wide, lanceolate-ovate, usually 3 times longer than wide, open, bases exserted from the upper sheaths at maturity, lowest node with 1-15 branches; branches scabrous to scabridulous, ascending, mostly branching above midlength, lower branches occasionally branching to near the base, spikelets somewhat clustered towards the tips, lower branches 2-10 cm, mostly longer than 3 cm; pedicels (0.5) 1-3.5 (6) mm; secondary panicles not present. Spikelets lanceolate to narrowly ovate, yellowish green to purple. Glumes unequal, 2-3.6 mm, 1 (3) -veined, scabrous on the midvein, occasionally also sparsely scabridulous over the body, acute to acuminate; callus hairs to 0.2 mm, sparse; lemmas 1.5-2.5 mm, usually smooth, sometimes scabridulous or pubescent, translucent to opaque, 5-veined, veins faint or prominent distally, apices acute to obtuse, usually entire, sometimes erose or toothed, teeth to about 0.4 mm, usually unawned, sometimes awned from midlength, awns to 2 mm, straight, not exserted, sometimes awned and unawned spikelets present on the same plant; paleas absent, or to 0.2 mm and thin; anthers 3, 0.5-1.2 mm. Caryopses 1-1.6 mm; endosperm semisoft. 2n = 42.

Distribution

Wash., B.C., Calif., Idaho, Mont., Wyo., Oreg., Nev.

Discussion

Agrostis oregonensis grows in wet habitats, such as stream and lake margins, damp woods, and meadows, in western North America, primarily in the Pacific Northwest from British Columbia to California and Wyoming. It has not been found in Mexico.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Agrostis oregonensis"
membranous +  and scarious +
not penicillate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
Toothed (?) +, Acute (?) +  and Obtuse (?) +
M.J. Harvey +
1 (?) +  and 3 (?) +
straight +
not exserted +
geniculate +
0 cm0 mm <br />0 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
rounded +  and keeled +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
10 cm100 mm <br />0.1 m <br /> (30 cm300 mm <br />0.3 m <br />) +
not evident +
scabridulous +
cross +, linear +  and narrowly lanceolate +
2mm;4mm +
scabrous +  and scabridulous +
spikelike +
0 cm0 mm <br />0 m <br /> (0.02 cm0.2 mm <br />2.0e-4 m <br />) +
hairy +  and glabrous +
Oregon redtop +
not branching +
12 cm120 mm <br />0.12 m <br /> (75 cm750 mm <br />0.75 m <br />) +
not woody +
Wash. +, B.C. +, Calif. +, Idaho +, Mont. +, Wyo. +, Oreg. +  and Nev. +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
sterile +  and bisexual +
compressed +
reduced +
(1)1.3-2(4) times longer than +
subtending +
scabridulous +
acute +  and acuminate +
unequal +
0.2 cm2 mm <br />0.002 m <br /> (0.36 cm3.6 mm <br />0.0036 m <br />) +
uncinate +
diffuse +  and dense +
translucent +  and opaque +
scabridulous +
lanceolate +  and ovate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
membranous +
truncate +  and rounded +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.63 cm6.3 mm <br />0.0063 m <br />) +
membranous +
inconspicuous +
lanceolate +
3 cm30 mm <br />0.03 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
concealed +  and prominent +
0 +  and 5 +
2 +  and 1 +
well-developed +
2-keeled +
minute +  and subequal +
0 cm0 mm <br />0 m <br /> (0.02 cm0.2 mm <br />2.0e-4 m <br />) +
8cm +  and 35cm +
lanceolate-ovate +
2.5 cm25 mm <br />0.025 m <br /> (14 cm140 mm <br />0.14 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (?) +
0.1 cm1 mm <br />0.001 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
dry +  and fleshy +
not prolonged +
hairy +  and glabrous +
scabridulous +  and smooth +
yellowish green +  and purple +
1 +  and 60 +
lanceolate +  and narrowly ovate +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Gramineae +
Agrostis oregonensis +
Agrostis +
species +
membranous +
2 +  and 5 +
not convergent +
prominent +  and faint +
scabrous +  and scabridulous +
stoloniferous +  and not rhizomatous +
plant +  and cespitose +
aquatic +  and terrestrial +