Aristida californica |
Aristida tuberculosa |
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California three-awn, Mojave three-awn |
seaside threeawn |
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Habit | Plants perennial; sometimes flowering the first year. | Plants annual. | ||||
Culms | 10-40 cm, highly branched above the base in age; internodes glabrous or pubescent, sometimes nearly lanose. |
(25) 40-100 cm, erect or decumbent to ascending near the base, highly branched above the base; nodes and internodes glabrous. |
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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 slightly shorter than the internodes, glabrous or pilose; collars often with a line of tangled hairs; ligules about 0.5 mm; blades 8-25 cm long, 2-4 mm wide, light green, flat to loosely involute, glabrous and smooth abaxially, scabridulous adaxially. |
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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. |
paniculate, 10-20 cm long, 3-10 cm wide; rachis nodes glabrous, scabrous, or strigose; primary branches 1-4 cm, stiffly ascending, with axillary pulvini, with 1-4 spikelets per branch. |
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Spikelets | appressed. |
loosely congested. |
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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. |
20-30 mm, yellowish-brown, 1-veined, apices narrowing to a 5-10 mm awn; upper glumes slightly longer than the lower glumes; calluses 3-4 mm; lemmas 10-14 mm, dark and mottled at maturity, glabrous or occasionally sparsely pubescent, not beaked, junction of the lemma and awns evident; awns twisted together basally into a 8-15 mm column, free portions 30-40 mm, those of the central and lateral awns similar in length, strongly curved to arcuate near the base, straight and strongly divergent to reflexed distally, disarticulating at the base of the column at maturity; anthers 3, about 2.5 mm, brownish. |
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Caryopses | 8-10 mm, dark brown. |
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2n | = 22. |
= unknown. |
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Aristida californica |
Aristida tuberculosa |
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Distribution |
AZ; CA
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AL; CT; DE; FL; GA; IA; IL; IN; KY; LA; MA; MD; MI; MN; MS; NC; NH; NJ; NY; SC; VA; WI
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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 tuberculosa grows in sandy fields, hills, pinelands, and disturbed areas. Along the Atlantic coastal fringe, it grows on maritime dunes; inland it is associated with xeric pine-oak sandhills. It is generally similar to A. desmantha, but has longer glumes, calluses, and awns. Like A. desmantha, A. tuberculosa is restricted to 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. 319. | ||||
Parent taxa | Poaceae > subfam. Aristidoideae > tribe Aristideae > Aristida | Poaceae > subfam. Aristidoideae > tribe Aristideae > Aristida | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Name authority | Thurb. | Nutt. | ||||
Web links |