Festuca idahoensis

Elmer
Common names: Idaho fescue Blue bunchgrass Bluebunch fescue
Endemic
Synonyms: Festuca idahoensis var. oregona
Treatment appears in FNA Volume 24. Treatment on page 438.
Please click on the illustration for a higher resolution version.
Illustrator: Cindy Roché

Copyright: Utah State University

Plants densely cespitose, without rhizomes. Culms 25-85 (100) cm, usually smooth, glabrous, occasionally scabrous below the inflorescences. Sheaths closed for less than 1/2 their length, smooth or scabrous, rarely pilose, persistent; collars glabrous; ligules 0.2-0.6 mm; blades (0.3) 0.5-0.9 (1.5) mm in diameter, conduplicate, abaxial surfaces smooth or scabrous, adaxial surfaces scabrous or pubescent, rarely pilose, often glaucous or bluish, veins (3) 5 (7), ribs (1) 3-5, well defined; abaxial sclerenchyma in 5-7 wide, irregular strands; adaxial sclerenchyma absent. Inflorescences (5) 7-15 (20) cm, loosely contracted or open, with 1-2 branches per node; branches usually somewhat spreading at maturity, sometimes erect, rarely reflexed, lower branches with 2+ spikelets. Spikelets (5.8) 7.5-13.5 (19) mm, with (2) 4-7 (9) florets. Glumes exceeded by the upper florets, ovatelanceolate to lanceolate, mostly smooth, sometimes scabrous distally; lower glumes 2.4-5 (6) mm; upper glumes 3-6 (8) mm; lemmas 5-8.5 (10) mm, scabrous at the apices, awns (1.5) 3-6 (7) mm, usually more than 1/2 as long as the lemma bodies; paleas shorter than to about as long as the lemmas, intercostal region scabrous or puberulent distally; anthers 2.4-4.5 mm; ovary apices glabrous. 2n = 28.

Distribution

Colo., N.Mex., Wash., Utah, Calif., Oreg., Alta., B.C., Sask., Mont., Wyo., Ariz., Idaho, Nev., S.Dak.

Discussion

Festuca idahoensis grows in grasslands, open forests, and sagebrush meadow communities, mostly east of the Cascade Mountains, from southern British Columbia eastward to southwestern Saskatchewan and southward to central California and New Mexico. It extends up to 3000 m in the southern part of its range. It is often a dominant plant, and provides good forage. The young foliage is particularly palatable.

Festuca idahoensis differs from F. arizonica (see previous), with which it is sometimes confused, in its less prominently ribbed blades and glabrous ovary apices. It has frequently been included in F. ovina (p. 422).

Selected References

None.

Lower Taxa

None.

"wider than long" is not a number."decumbent" is not a number."longest" is not a number.

... more about "Festuca idahoensis"
pilose +, pubescent +, puberulent +, scabrous +  and glabrous +
membranous +  and scarious +
glaucous +, pilose +, pubescent +  and scabrous +
0.24 cm2.4 mm <br />0.0024 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
awned +  and entire +
hispidulous +
bidentate +
Stephen J. Darbyshire +  and Leon E. Pavlickf +
1 (?) +  and 3 (?) +
1.5 cm15 mm <br />0.015 m <br /> (?) +
straight +
basal +  and terminal +
/2 +  and 1 +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
keeled +  and rounded +
swelling +
0.3 cm3 mm <br />0.003 m <br /> (?) +
not deciduous +  and deciduous +
not evident +
flat +, convolute +  and setaceous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
spikelike +
pubescent +  and glabrous +
Idaho fescue +, Blue bunchgrass +  and Bluebunch fescue +
not branching +
ascending +  and erect +
25 cm250 mm <br />0.25 m <br /> (85 cm850 mm <br />0.85 m <br />) +
not woody +
Colo. +, N.Mex. +, Wash. +, Utah +, Calif. +, Oreg. +, Alta. +, B.C. +, Sask. +, Mont. +, Wyo. +, Ariz. +, Idaho +, Nev. +  and S.Dak. +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
4 +  and 7 +
compressed +
reduced +
shorter or longer +
subtending +
ovatelanceolate +  and lanceolate +
unequal +  and subequal +
persisting +
uncinate +
7 cm70 mm <br />0.07 m <br /> (15 cm150 mm <br />0.15 m <br />) +
puberulent +  and scabrous +
1-7(9)-veined +
awned +  and entire +
bidentate +
0.5 cm5 mm <br />0.005 m <br /> (0.85 cm8.5 mm <br />0.0085 m <br />) +
coriaceous +, chartaceous +  and membranous +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
membranous +
inconspicuous +
lanceolate +
reflexed +  and erect +
0.24 cm2.4 mm <br />0.0024 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
concealed +  and prominent +
2 +  and 1 +
with hispidulous apices +  and glabrous +
well-developed +
2-keeled +
spikelike +
dry +  and fleshy +
glabrous +, pubescent +  and scabrous +
3 +  and 5 +
persistent +
pilose +, scabrous +  and smooth +
1 +  and 60 +
compressed +
0.75 cm7.5 mm <br />0.0075 m <br /> (1.35 cm13.5 mm <br />0.0135 m <br />) +
1 +  and 3 +
simple +  and compound +
2 (?) +  and 3 (?) +
Festuca idahoensis var. oregona +
Festuca idahoensis +
Festuca sect. Festuca +
species +
membranous +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
parallel +  and converging +
obscure +  and prominent +
stoloniferous +  and rhizomatous +
plant +  and cespitose +
aquatic +  and terrestrial +