Aristida purpurea var. longiseta

(Steud.) Vasey
Common names: Red threeawn
Synonyms: Aristida purpurea var. robusta Aristida longiseta var. robusta Aristida longiseta
Treatment appears in FNA Volume 25. Treatment on page 332.

Culms 10-40 (50) cm. Leaves sometimes mostly basal, sometimes mostly cauline; blades 4-16 cm, usually involute. Panicles 5-15 cm; primary branches appressed or ascending at the base, without axillary pulvini, stout and straight to delicate and drooping distally, usually neither flexible nor tangled. Lower glumes 8-12 mm; upper glumes (14) 16-25 mm; lemmas 12-16 mm long, apices 0.3-0.8 mm wide; awns subequal, 40-100 (140) mm long, 0.2-0.5 mm wide at the base. 2n = 22, 44, 66, 88.

Distribution

Wyo., Colo., N.Mex., Tex., La., Utah, Calif., Minn., Kans., N.Dak., Nebr., Okla., S.Dak., Oreg., Mont., Alta., B.C., Man., Sask., Wash., Iowa, N.C., S.C., Ariz., Idaho, Nev.

Discussion

Aristida purpurea var. longiseta grows on sandy or rocky slopes and plains, and in barren soils of disturbed ground from western Canada to northern Mexico. It is the most variable variety of Aristida purpurea, ranging from short plants with basal leaves and short panicles suggestive of var. fendleriana, to tall plants with long cauline leaves and long, drooping panicles resembling var. purpurea. The length of its glumes, width of its lemma apex, and the length and thickness of its awns distinguish it from all the other varieties. The callus and long, stiff awns are especially troublesome to sheep and cattle.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

88 +, 66 +, 44 +  and 22 +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.3mm;0.8mm +
Kelly W. Allred +
(Steud.) Vasey +
not disarticulating +
divaricate +
1 (?) +  and 3 (?) +
8 cm80 mm <br />0.08 m <br /> (?) +
straight +
4 cm40 mm <br />0.04 m <br /> (10 cm100 mm <br />0.1 m <br />) +
not conspicuous +
subequal +
1.3 cm13 mm <br />0.013 m <br /> (14 cm140 mm <br />0.14 m <br />) +
0.2mm;0.5mm +
keeled +  and rounded +
coiled +, disarticulating +  and twisted +
spreading +  and appressed +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
straight +
0 cm0 mm <br />0 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
4 cm40 mm <br />0.04 m <br /> (25 cm250 mm <br />0.25 m <br />) +
scabridulous +
curled +, tightly involute +  and flat +
4 cm40 mm <br />0.04 m <br /> (16 cm160 mm <br />0.16 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
spikelike +
well-developed +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
tan +  and chestnut +
0.6 cm6 mm <br />0.006 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
non-radiate +  and radiate +
pilose +  and glabrous +
Red threeawn +
erect +  and ascending +
10 cm100 mm <br />0.1 m <br /> (40 cm400 mm <br />0.4 m <br />) +
not woody +
Wyo. +, Colo. +, N.Mex. +, Tex. +, La. +, Utah +, Calif. +, Minn. +, Kans. +, N.Dak. +, Nebr. +, Okla. +, S.Dak. +, Oreg. +, Mont. +, Alta. +, B.C. +, Man. +, Sask. +, Wash. +, Iowa +, N.C. +, S.C. +, Ariz. +, Idaho +  and Nev. +
large +  and small +
thread-like +
capillary +
germination +
pistillate +  and staminate +
sometimes longer +
compressed +  and terete +
subtending +
acute +  and acuminate +
unequal +
straight +
3 cm30 mm <br />0.03 m <br /> (?) +  and 30 cm300 mm <br />0.3 m <br /> (?) +
2 cm20 mm <br />0.02 m <br /> (12 cm120 mm <br />0.12 m <br />) +
1.3 cm13 mm <br />0.013 m <br /> (14 cm140 mm <br />0.14 m <br />) +
cauline +  and basal +
whitish +  and purplish +
1.2 cm12 mm <br />0.012 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
tuberculate +  and scabridulous +
fusiform +
0.6 cm6 mm <br />0.006 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
coriaceous +
indistinguishable +
0 cm0 mm <br />0 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
inconspicuous +
scabridulous +  and smooth +
0.8 cm8 mm <br />0.008 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
concealed +  and prominent +
with straight +  and glabrous +
2 +  and 1 +
concealing +
0 +  and 1/2 +
5 cm50 mm <br />0.05 m <br /> (15 cm150 mm <br />0.15 m <br />) +
dry +  and fleshy +
drooping;ascending;appressed +
3 cm30 mm <br />0.03 m <br /> (6 cm60 mm <br />0.06 m <br />) +
not prolonged +
not disintegrating +
shorter or longer +
1 (?) +  and Anatomy (?) +
1 +  and 60 +
1 +  and 3 +
triangular +  and dome--shaped +
2 (?) +  and 3 (?) +
Aristida purpurea var. robusta +, Aristida longiseta var. robusta +  and Aristida longiseta +
Aristida purpurea var. longiseta +
Aristida purpurea +
variety +
membranous +
1.6 cm16 mm <br />0.016 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
plant +  and cespitose +
aquatic +  and terrestrial +