Aristida californica |
Aristida stricta |
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California three-awn, Mojave three-awn |
pineland threeawn, wiregrass |
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Habit | Plants perennial; sometimes flowering the first year. | Plants perennial; cespitose, occasionally with rhizomes. | ||||
Culms | 10-40 cm, highly branched above the base in age; internodes glabrous or pubescent, sometimes nearly lanose. |
60-120 cm, stiffly erect, unbranched. |
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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. |
basal or nearly basal; sheaths shorter than the internodes, smooth and mostly glabrous abaxially, sometimes with a line of widely spaced, 0.5-1 mm hairs over the midvein, not disintegrating into threadlike fibers at maturity; collars glabrous, sometimes with a few conspicuous hairs at the sides; ligules 0.1-0.3 mm; blades 15-50 cm long, 0.3-1 mm wide, tightly involute, stiff, yellow-green, abaxial surfaces villous on both sides of the midvein, at least on the basal portion, hairs 0.6-1.5 mm, adaxial surfaces densely scabrous or densely short pubescent. |
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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, 20-35 cm, 5-8 mm wide; nodes glabrous; primary branches 2-5 cm, appressed, without axillary pulvini, with 4-12 spikelets, spikelet-bearing to the base. |
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Spikelets | appressed. |
appressed. |
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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. |
subequal, glabrous, light brown or tan, usually 1(2)-veined, bifid and awned, awns 1.5-2.5 mm; lower glumes 7-10 mm; upper glumes 6-9 mm; calluses 0.4-0.6 mm; lemmas 6-9 mm, glabrous, light-colored when young, reddish when mature, column 1-2 mm, not twisted, junction with the awns inconspicuous; awns (7)10-15(22) mm, subequal, usually horizontally spreading or curving downward, not disarticulating at maturity; anthers 3, about 3 mm, reddish-brown. |
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Caryopses | 4-5 mm, chestnut brown. |
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2n | = 22. |
= unknown. |
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Aristida californica |
Aristida stricta |
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Distribution |
AZ; CA
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NC; SC
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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 stricta grows in pine barrens and sandy fields of the coastal plain from Louisiana to North Carolina. Peet (1993) segregated northern populations of A. stricta as a separate species, A. beyrichiana Trin. & Rupr., based on pubescence patterns of the sheath and blades. Investigations into alloyzyme diversity (Walters et al. 1994), anatomy, morphology, and phenotypic expression (garden transplants) led Kesler (2000) to conclude that such a segregation was not justified; pubescence patterns particularly were inconclusive. Consequently, A. beyrichiana is treated here as part of A. stricta. (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. 335. | ||||
Parent taxa | Poaceae > subfam. Aristidoideae > tribe Aristideae > Aristida | Poaceae > subfam. Aristidoideae > tribe Aristideae > Aristida | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | A. beyrichiana | |||||
Name authority | Thurb. | Michx. | ||||
Web links |