Agrostis exarata

Trin.
Common names: Spike bent
Synonyms: Agrostis longiligula var. australis Agrostis longiligula Agrostis exarata var. purpurascens Agrostis exarata var. pacifica Agrostis exarata var. monolepis Agrostis exarata var. minor Agrostis exarata subsp. minor Agrostis ampla Agrostis alaskana
Treatment appears in FNA Volume 24. Treatment on page 651.
Please click on the illustration for a higher resolution version.
Illustrator: Sandy Long

Copyright: Utah State University

Plants perennial; usually cespitose, sometimes rhizomatous, not stoloniferous. Culms 8-100 cm, erect or decumbent at the base, sometimes rooting at the lower nodes, with (2) 3-6 (8) nodes. Leaves mostly cauline; sheaths smooth or slightly scabrous; ligules (1) 1.7-8 (11.2) mm, dorsal surfaces scabrous, apices truncate to obtuse, lacerate to erose; blades 4-15 cm long, 2-7 mm wide, flat. Panicles (3) 5-30 cm long, 0.5-4 cm wide, contracted, spikelike, oblong, or lanceolate, usually dense, rarely more open, sometimes interrupted near the base, bases usually exserted, rarely enclosed by the upper sheaths at maturity, lowest node with 1-5 branches; branches scabrous, ascending to appressed, spikelet-bearing to or near the base, usually hidden by the spikelets, spikelets crowded, lower branches 1-2 (4) cm; pedicels 0.2-4.3 mm. Spikelets lanceolate to narrowly ovate, greenish to purplish. Glumes subequal to equal, 1.5-3.5 mm, scabrous on the midvein and sometimes on the back, 1 (3) -veined, acute, elongate-acuminate, with an awnlike tip to 1 mm; callus hairs to 0.3 mm, sparse to abundant; lemmas 1.2-2.2 mm, smooth, translucent to opaque, 5-veined, veins prominent distally or obscure throughout, apices acute, entire or toothed, teeth no more than 0.12 mm, unawned or awned from above midlength, awns to 3.5 mm, straight or geniculate; paleas absent or to 0.5 mm; anthers 3, 0.3-0.6 mm. Caryopses 0.9-1.2 mm; endosperm solid or soft. 2n = 28, 42, 56.

Distribution

Oreg., Colo., Alta., B.C., N.W.T., Sask., Yukon, Tex., Nebr., Okla., S.Dak., Utah, Alaska, Idaho, Mont., Vt., Wyo., Wash., Ky., Ariz., Calif., Nev., N.Mex.

Discussion

Agrostis exarata is common and widely distributed in western North America, usually growing in moist ground in open woodlands, river valleys, tidal marshes, and swamp and lake margins; it also grows in dry habitats such as grasslands and shrublands. It extends from Alaska into Mexico, and is also found in Kamchatka and the Kuril Islands. Eastern North American records probably reflect introductions. It readily colonizes roadsides and bare soil, and exhibits ecological and developmental flexibility. Agrostis exarata is recognized here as a single, variable species that includes what others have treated as distinct species or varieties. Cytotaxonomic study might clarify the basis of the observed variation. Agrostis exarata appears to be related to A. densiflora (see below).

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Agrostis exarata"
56 +, 42 +  and 28 +
membranous +  and scarious +
not penicillate +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
awned +, truncate +  and entire +
toothed +, entire +, acute +, lacerate +, truncate +  and obtuse +
M.J. Harvey +
1 (?) +  and 3 (?) +
straight +
basal +  and terminal +
geniculate +
0 cm0 mm <br />0 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
rounded +  and keeled +
pseudopetiolate +  and branching +
swelling +
4 cm40 mm <br />0.04 m <br /> (15 cm150 mm <br />0.15 m <br />) +
not evident +
scabridulous +
cross +, linear +  and narrowly lanceolate +
0.2 cm2 mm <br />0.002 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
ascending;appressed +
spikelike +
1 cm10 mm <br />0.01 m <br /> (?) +
sparse +  and abundant +
0 cm0 mm <br />0 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
hairy +  and glabrous +
Spike bent +
decumbent +  and erect +
8 cm80 mm <br />0.08 m <br /> (100 cm1,000 mm <br />1 m <br />) +
not woody +
Oreg. +, Colo. +, Alta. +, B.C. +, N.W.T. +, Sask. +, Yukon +, Tex. +, Nebr. +, Okla. +, S.Dak. +, Utah +, Alaska +, Idaho +, Mont. +, Vt. +, Wyo. +, Wash. +, Ky. +, Ariz. +, Calif. +, Nev. +  and N.Mex. +
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 +
elongate-acuminate +  and acute +
subequal +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
uncinate +
diffuse +  and dense +
translucent +  and opaque +
pubescent +  and glabrous +
warty-tuberculate +  and scabridulous +
lanceolate +  and ovate +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.22 cm2.2 mm <br />0.0022 m <br />) +
membranous +
0.17 cm1.7 mm <br />0.0017 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
membranous +
inconspicuous +
lanceolate +
1 cm10 mm <br />0.01 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 />) +
8 (?) +  and 2 (?) +
concealed +  and prominent +
3 +  and 6 +
2 +  and 1 +
well-developed +
2-keeled +
minute +  and subequal +
interrupted +  and open +
5cm +  and 30cm +
lanceolate +, oblong +  and spikelike +
0.5 cm5 mm <br />0.005 m <br /> (4 cm40 mm <br />0.04 m <br />) +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.43 cm4.3 mm <br />0.0043 m <br />) +
dry +  and fleshy +
not prolonged +
hairy +  and glabrous +
scabrous +  and scabridulous +
greenish +  and purplish +
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 (?) +
Agrostis longiligula var. australis +, Agrostis longiligula +, Agrostis exarata var. purpurascens +, Agrostis exarata var. pacifica +, Agrostis exarata var. monolepis +, Agrostis exarata var. minor +, Agrostis exarata subsp. minor +, Agrostis ampla +  and Agrostis alaskana +
Agrostis exarata +
Agrostis +
species +
awnlike +
membranous +
not convergent +
obscure +  and prominent +
scabrous +  and scabridulous +
not stoloniferous +  and rhizomatous +
plant +  and cespitose +
aquatic +  and terrestrial +