Aristida divaricata

Humb. & Bonpl. ex Willd.
Common names: Poverty grass
Treatment appears in FNA Volume 25. Treatment on page 323.

Plants perennial; cespitose. Culms 25-70 cm, erect or prostrate, unbranched or sparingly branched. Leaves tending to basal; sheaths longer than the internodes, glabrous except at the summit; collars densely pilose; ligules 0.5-1 mm; blades 5-20 cm long, 1-2 mm wide, flat to loosely involute, glabrous. Inflorescences paniculate, 10-30 cm long, 6-25 cm wide, peduncles flattened and easily broken; rachis nodes glabrous or with hairs, hairs to 0.5 mm; primary branches 5-13 cm, stiffly divaricate to reflexed, with axillary pulvini, usually naked on the basal 1/2; secondary branches usually well-developed. Spikelets overlapping, usually appressed, sometimes divergent and the pedicels with axillary pulvini. Glumes 8-12 mm, 1-veined, acuminate or shortly awned, awns to 4 mm; calluses about 0.5 mm; lemmas 8-13 mm long, the terminal 2-3 mm with 4 or more twists when mature, narrowing to 0.1-0.2 mm wide just below the awns, junction with the awns not evident; awns (7) 10-20 mm, not disarticulating at maturity; central awns almost straight to curved at the base, ascending to somewhat divergent distally; lateral awns slightly thinner and from much to slightly shorter than the central awns, ascending to divergent; anthers 3, 0.8-1 mm. Caryopses 8-10 mm, light-brown. 2n = 22.

Distribution

Kans., Okla., Colo., Calif., N.Mex., Tex., Ariz.

Discussion

Aristida divaricata grows on dry hills and plains, especially in pinyon-juniper-grassland zones, from the southwestern United States through Mexico to Guatemala. It occasionally intergrades with A. havardii, but that species has lemma beaks that are straight or have only 1-2 twists, shorter primary branches, usually no secondary branches, and pedicels that more frequently have axillary pulvini so the spikelets are more frequently divergent than in A. divaricata.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Aristida divaricata"
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
Kelly W. Allred +
Humb. & Bonpl. ex Willd. +
not disarticulating +
1 (?) +  and 3 (?) +
7 cm70 mm <br />0.07 m <br /> (?) +
straight +
ascending +  and spreading +
not evident +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
wide;narrowing +
keeled +  and rounded +
coiled +, disarticulating +  and twisted +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
straight +
5 cm50 mm <br />0.05 m <br /> (20 cm200 mm <br />0.2 m <br />) +
flat +  and loosely involute +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
spikelike +
well-developed +
0.5 cm5 mm <br />0.005 m <br /> (?) +
0.8 cm8 mm <br />0.008 m <br /> (1 cm10 mm <br />0.01 m <br />) +
non-radiate +  and radiate +
straight +  and curved +
Poverty grass +
branched +  and unbranched +
prostrate +  and erect +
25 cm250 mm <br />0.25 m <br /> (70 cm700 mm <br />0.7 m <br />) +
not woody +
Kans. +, Okla. +, Colo. +, Calif. +, N.Mex. +, Tex. +  and Ariz. +
large +  and small +
capillary +
germination +
pistillate +  and staminate +
sometimes longer +
compressed +  and terete +
subtending +
awned +  and acuminate +
0.8 cm8 mm <br />0.008 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
0 cm0 mm <br />0 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
10 cm100 mm <br />0.1 m <br /> (?) +  and 30 cm300 mm <br />0.3 m <br /> (?) +
6 cm60 mm <br />0.06 m <br /> (25 cm250 mm <br />0.25 m <br />) +
wide +  and narrowing +
much to slightly shorter +
cauline +  and basal +
0.8 cm8 mm <br />0.008 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
scabridulous +
fusiform +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
coriaceous +
indistinguishable +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
inconspicuous +
concealed +  and prominent +
2 +  and 1 +
concealing +
0 +  and 1/2 +
flattened +
dry +  and fleshy +
5 cm50 mm <br />0.05 m <br /> (13 cm130 mm <br />0.13 m <br />) +
not prolonged +
with hairs +  and glabrous +
1 (?) +  and Anatomy (?) +
divergent +  and overlapping +
1 +  and 60 +
1 +  and 3 +
triangular +  and dome--shaped +
2 (?) +  and 3 (?) +
Gramineae +
Aristida divaricata +
Aristida +
species +
membranous +
plant +  and cespitose +
aquatic +  and terrestrial +