Aristida purpurea var. purpurea

Common names: Purple threeawn
Treatment appears in FNA Volume 25. Treatment on page 333.

Culms 26-60 cm. Blades 3-17 cm, basal and cauline, involute. Panicles 10-25 cm; primary branches appressed at the base, without axillary pulvini, capillary, drooping to sinuous distally; pedicels capillary, usually lax to sinuous. Lower glumes 4-9 mm; upper glumes 7-16 mm; lemmas 6-12 mm long, narrowing to 0.1-0.3 mm wide; awns subequal, (15) 20-60 mm long, 0.1-0.3 mm wide at the base. 2n = 22, 44, 66, 88.

Distribution

Kans., Okla., Colo., N.Mex., Tex., La., Utah, Calif., Ariz., Ark., Nev.

Discussion

Aristida purpurea var. purpurea grows in sandy to clay soils, along right of ways, or on dry slopes and mesas. Its range extends from the Flora region to Mexico and Cuba. As treated here, var. purpurea is, admittedly, a broadly defined taxon, incorporating slender plants with small spikelets that used to be referred to A. roemeriana Scheele, but also occasional plants with somewhat flexible branches that are intermediate to var. wrightii and var. nealleyi.

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 />) +
0.1mm;0.8mm +
Kelly W. Allred +
not disarticulating +
divaricate +
1 (?) +  and 3 (?) +
8 cm80 mm <br />0.08 m <br /> (?) +
straight +
2 cm20 mm <br />0.02 m <br /> (6 cm60 mm <br />0.06 m <br />) +
not conspicuous +
subequal +
1.3 cm13 mm <br />0.013 m <br /> (14 cm140 mm <br />0.14 m <br />) +
0.1mm;0.3mm +
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 />) +
cauline +  and basal +
scabridulous +
curled +, tightly involute +  and flat +
3 cm30 mm <br />0.03 m <br /> (17 cm170 mm <br />0.17 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 +
Purple threeawn +
erect +  and ascending +
26 cm260 mm <br />0.26 m <br /> (60 cm600 mm <br />0.6 m <br />) +
not woody +
Kans. +, Okla. +, Colo. +, N.Mex. +, Tex. +, La. +, Utah +, Calif. +, Ariz. +, Ark. +  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 +
0.6 cm6 mm <br />0.006 m <br /> (1.2 cm12 mm <br />0.012 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 +
wide +  and narrowing +
indistinguishable +
0 cm0 mm <br />0 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
inconspicuous +
scabridulous +  and smooth +
0.4 cm4 mm <br />0.004 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
concealed +  and prominent +
with straight +  and glabrous +
2 +  and 1 +
concealing +
0 +  and 1/2 +
10 cm100 mm <br />0.1 m <br /> (25 cm250 mm <br />0.25 m <br />) +
capillary +
dry +  and fleshy +
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 roemeriana +  and Aristida purpurea var. laxiflora +
Aristida purpurea var. purpurea +
Aristida purpurea +
variety +
membranous +
0.7 cm7 mm <br />0.007 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
plant +  and cespitose +
aquatic +  and terrestrial +