Aristida purpurea var. wrightii

(Nash) Allred
Common names: Wright's threeawn
Synonyms: Aristida wrightii unknown
Treatment appears in FNA Volume 25. Treatment on page 333.
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Culms 45-100 cm. Blades 10-25 cm, involute or flat. Panicles (12)14-30 cm; primary branches usually erect, without axillary pulvini, stiff, straight, lower nodes associated with 2-10 spikelets. Glumes tan to brown, fading to stramineous. Lower glumes 5-10 mm; upper glumes 9-16 mm; lemmas 8-14 mm long, narrowing to 0.2-0.3 mm wide; awns (8)20-35 mm long, 0.2-0.3 mm wide at the base, lateral awns usually subequal to the central awn, rarely 1-3 mm. 2n = 22, 44, 66.

Distribution

N.Mex., Tex., Colo., Utah, Calif., Okla., Ariz., Nev.

Discussion

Aristida purpurea var. wrightii grows on sandy to gravelly hills and flats from the southwestern United States to southern Mexico. It is the most robust variety of A. purpurea, and has dark, stout awns and long panicles. It may be confused with </i>var.<i> nealleyi, which has narrower lemmas and awns and a light-colored panicle, but it also intergrades with </i>var.<i> purpurea and </i>var.<i> parishii. Aristida purpurea forma brownii (Warnock) Allred & Valdes-Reyna refers to plants with short central awns and lateral awns that are only 1-3 mm long.

References

None.

Lower Taxa

No lower taxa listed.