Aristida oligantha

Michx.
Common names: Oldfield threeawn
Treatment appears in FNA Volume 25. Treatment on page 326.

Plants annual. Culm 25-55 cm, erect or geniculate at the base, highly branched. Leaves cauline; sheaths usually shorter than the internodes, lowermost sheaths appressed-pilose basally; collars glabrous; ligules less than 0.5 mm; blades usually 4-12 cm long, 0.5-1.5 mm wide, flat or loosely involute, somewhat lax, glabrous or scabridulous, pale green. Inflorescences spicate or racemose, (5) 7-20 cm long, 2-4 cm wide; primary branches rarely developed. Spikelets divergent, pedicels with axillary pulvini. Glumes unequal, glabrous, brownish-green with a purple tinge; lower glumes (9) 12-22 (28) mm, 3-7-veined, midvein extended into a 1-13 mm awn between 2 delicate setae; upper glumes (7) 11-20 (24) mm, 1-veined; calluses 0.5-2 mm; lemmas (9) 12-22 (23) mm, glabrous, light-colored, often mottled; awns (8) 12-65 (70) mm, subequal, spreading; anthers usually 1 and less than 0.5 mm, rarely 3 and 3-4 mm. Caryopses 8-14 mm, brown. 2n = 22.

Distribution

Del., D.C., Wis., W.Va., Fla., Wyo., N.H., N.J., N.Mex., Tex., La., Tenn., N.C., S.C., Pa., B.C., Ont., Conn., Mass., R.I., Vt., Kans., Nebr., Okla., S.Dak., N.Y., Va., Calif., Ala., Ark., Ill., Ga., Ind., Iowa, Ariz., Idaho, Maine, Md., Ohio, Mo., Minn., Mich., Miss., Ky., Oreg.

Discussion

Aristida oligantha grows in waste places, dry fields, roadsides, along railroads, and in burned areas, usually in sandy soil. It has been reported from Coahuila, Mexico, but is otherwise unknown outside southern Canada and the United States.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number."elongated" is not a number.

... more about "Aristida oligantha"
3 +  and 1 +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Kelly W. Allred +
Michx. +
1 (?) +  and 3 (?) +
8 cm80 mm <br />0.08 m <br /> (?) +
straight +
subequal +
1.2 cm12 mm <br />0.012 m <br /> (6.5 cm65 mm <br />0.065 m <br />) +
keeled +  and rounded +
coiled +, disarticulating +  and twisted +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
straight +
0.1 cm1 mm <br />0.001 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
4 cm40 mm <br />0.04 m <br /> (12 cm120 mm <br />0.12 m <br />) +
scabridulous +
involute +  and flat +
0.5mm;1.5mm +
spikelike +
well-developed +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
non-radiate +  and radiate +
Oldfield threeawn +
geniculate +
25 cm250 mm <br />0.25 m <br /> (55 cm550 mm <br />0.55 m <br />) +
not woody +
Del. +, D.C. +, Wis. +, W.Va. +, Fla. +, Wyo. +, N.H. +, N.J. +, N.Mex. +, Tex. +, La. +, Tenn. +, N.C. +, S.C. +, Pa. +, B.C. +, Ont. +, Conn. +, Mass. +, R.I. +, Vt. +, Kans. +, Nebr. +, Okla. +, S.Dak. +, N.Y. +, Va. +, Calif. +, Ala. +, Ark. +, Ill. +, Ga. +, Ind. +, Iowa +, Ariz. +, Idaho +, Maine +, Md. +, Ohio +, Mo. +, Minn. +, Mich. +, Miss. +, Ky. +  and Oreg. +
large +  and small +
capillary +
germination +
pistillate +  and staminate +
sometimes longer +
compressed +  and terete +
brownish-green with a purple tinge +
subtending +
acute +  and acuminate +
unequal +
7cm +  and 20cm +
mottled +  and light-colored +
scabridulous +
fusiform +
1.2 cm12 mm <br />0.012 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
coriaceous +
indistinguishable +
0 cm0 mm <br />0 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
inconspicuous +
1.2 cm12 mm <br />0.012 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
extended +
concealed +  and prominent +
2 +  and 1 +
concealing +
0 +  and 1/2 +
dry +  and fleshy +
divaricate +  and divergent +
ascending;usually appressed;ascending +
not prolonged +
1 (?) +  and Anatomy (?) +
1 +  and 60 +
1 (?) +  and 3 (?) +
triangular +  and dome--shaped +
2 (?) +  and 3 (?) +
Gramineae +
Aristida oligantha +
Aristida +
species +
membranous +
1.1 cm11 mm <br />0.011 m <br /> (2 cm20 mm <br />0.02 m <br />) +
aquatic +  and terrestrial +