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
... more about "Hesperostipa comata"
Mary E. Barkworth +
(Trin. & Rupr.) Barkworth +
Needle-and-thread +
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 +
Stipa comata subsp. intonsa +  and Stipa comata +
Hesperostipa comata +
Hesperostipa +
species +