Hesperostipa comata

(Trin. & Rupr.) Barkworth
Common names: Needle-and-thread
Synonyms: Stipa comata subsp. intonsa Stipa comata
Treatment appears in FNA Volume 24. Treatment on page 158.

Culms 12-110 cm; lower nodes glabrous or pubescent. Lower sheaths glabrous or pubescent, not ciliate; ligules of lower leaves 1-6.5 mm, scarious, usually acute, sometimes trun¬cate, often lacerate; ligules of upper leaves to 7 mm; blades 0.5-4 mm wide, usually involute. Panicles 10-32 cm, contracted. Glumes 16-35 mm, 3-5-veined; lower glumes 18-35 mm; upper glumes 1-3 mm shorter; florets 7-13 mm; calluses 2-4 mm; lemmas evenly pubescent, hairs about 1 mm, white, sometimes glabrous immediately above the callus; awns 65-225 mm, first 2 segments scabrous to strigose, hairs shorter than 1 mm, terminal segment scabridulous.

Distribution

Wash., Wis., Wyo., N.Mex., Tex., Ill., Ind., Kans., N.Dak., N.Y., Okla., R.I., S.Dak., Nev., Colo., Calif., Nebr., Mont., Oreg., Iowa, Ariz., Idaho, Utah, Minn., Mich., Alta., B.C., Man., Ont., Sask., Yukon

Discussion

Hesperostipa comata is found primarily in the cool deserts, grasslands, and pinyon-juniper forests of western North America. The two subspecies overlap geographically, but are only occasionally sympatric. Both are primarily cleistogamous.

Selected References

None.

Key

1 Terminal awn segment 40-120 mm long, sinuous to curled at maturity; lower cauline nodes usually concealed by the sheaths; panicles often partially enclosed in the uppermost sheath at maturity Hesperostipa comata subsp. comata
1 Terminal awn segment 30-80 mm long, straight; lower cauline nodes usually exposed; panicles usually completely exserted at maturity Hesperostipa comata subsp. intermedia

"decumbent" is not a number."prolonged" is not a number.

... more about "Hesperostipa comata"
membranous +  and scarious +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
prow-tipped +
awned +, bifid +, bilobed +  and entire +
not sharp +  and acute +
indurate +
Mary E. Barkworth +
(Trin. & Rupr.) Barkworth +
twisted +  and not branched +
1 (?) +  and 3 (?) +
subterminal +  and eccentric +
scabrous +  and pilose +
6.5 cm65 mm <br />0.065 m <br /> (22.5 cm225 mm <br />0.225 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
4 cm40 mm <br />0.04 m <br /> (40 cm400 mm <br />0.4 m <br />) +
not evident +
cross +, linear +  and narrowly lanceolate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
spikelike +
well-developed +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Needle-and-thread +
not branching +
perennial +  and annual +
12 cm120 mm <br />0.12 m <br /> (110 cm1,100 mm <br />1.1 m <br />) +
not woody +
Wash. +, Wis. +, Wyo. +, N.Mex. +, Tex. +, Ill. +, Ind. +, Kans. +, N.Dak. +, N.Y. +, Okla. +, R.I. +, S.Dak. +, Nev. +, Colo. +, Calif. +, Nebr. +, Mont. +, Oreg. +, Iowa +, Ariz. +, Idaho +, Utah +, Minn. +, Mich. +, Alta. +, B.C. +, Man. +, Ont. +, Sask. +  and Yukon +
0 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
cylindrical +
7mm +  and 13mm +
15mm +  and 60mm +
subtending +
tapering +
1.6 cm16 mm <br />0.016 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
membranous +
2mm +  and 4mm +
uncinate +
1 cm10 mm <br />0.01 m <br /> (1 cm10 mm <br />0.01 m <br />) +
solid +  and hollow +
basally concentrated +  and evenly distributed +
0.1 cm1 mm <br />0.001 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
ovate +, rectangular +  and lanceolate +
membranous +
inconspicuous +
lanceolate +
fleshy +  and membranous +
1.8 cm18 mm <br />0.018 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
pubescent +  and glabrous +
pubescent +  and glabrous +
concealed +  and prominent +
2 +  and 1 +
pubescent +  and glabrous +
well-developed +
reduced +
coriaceous +
10 cm100 mm <br />0.1 m <br /> (32 cm320 mm <br />0.32 m <br />) +
dry +  and fleshy +
not prolonged +
1 +  and 60 +
unisexual +  and bisexual +
laterally compressed +  and terete +
1.5 cm15 mm <br />0.015 m <br /> (6 cm60 mm <br />0.06 m <br />) +
1 +  and 3 +
simple +  and compound +
2 (?) +  and 3 (?) +
Stipa comata subsp. intonsa +  and Stipa comata +
Hesperostipa comata +
Hesperostipa +
species +
membranous +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
inconspicuous +
plant +  and cespitose +
aquatic +  and terrestrial +