Aristida californica |
Aristida oligantha |
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California three-awn, Mojave three-awn |
Oldfield three-awn, prairie three-awn |
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Habit | Plants perennial; sometimes flowering the first year. | Plants annual. | ||||
Leaves | cauline; sheaths shorter than the internodes, glabrous or puberulent; collars glabrous or pubescent at the sides; ligules 0.5-1 mm; blades usually less than 6 cm long, 0.5-1 mm wide, pale green, involute, glabrous or puberulent abaxially. |
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. |
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Inflorescences | paniculate or racemose, 5-10 cm long, 1-2 cm wide, with few spikelets; rachis nodes glabrous or with straight hairs; primary branches 1-2 cm, appressed, without axillary pulvini. |
spicate or racemose, (5)7-20 cm long, 2-4 cm wide; primary branches rarely developed. |
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Spikelets | appressed. |
divergent, pedicels with axillary pulvini. |
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Glumes | unequal, 1-2-veined; lower glumes 4-10 mm; upper glumes 7-15 mm; calluses about 1 mm; lemmas 5-7 mm, purple or mottled, junction of the lemma and awns evident; awns twisted together basally into a 4-26 mm column, free portions 12-50 mm, those of the central and lateral awns similar in length, curved to arcuate basally, straight and divergent distally, disarticulating at the base of the column at maturity; anthers 3, about 2 mm long. |
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. |
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Caryopses | 8-14 mm, brown. |
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Culm(s) | 10-40 cm, highly branched above the base in age; internodes glabrous or pubescent, sometimes nearly lanose. |
25-55 cm, erect or geniculate at the base, highly branched. |
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2n | = 22. |
= 22. |
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Aristida californica |
Aristida oligantha |
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Distribution |
AZ; CA
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AL; AR; AZ; CA; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NM; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; VA; VT; WI; WV; WY; BC; ON
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Discussion | The range of both varieties of Aristida californica extends from the southwestern United States into northwestern Mexico. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 25, p. 319. | FNA vol. 25, p. 326. | ||||
Parent taxa | Poaceae > subfam. Aristidoideae > tribe Aristideae > Aristida | Poaceae > subfam. Aristidoideae > tribe Aristideae > Aristida | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Name authority | Thurb. | Michx. | ||||
Web links |
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