Aristida dichotoma var. dichotoma |
Aristida dichotoma |
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churchmouse threeawn |
churchmouse three-awn |
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Habit | Plants annual. | |||||
Culms | 15-60 cm, erect or geniculate at the base, branching at most of the nodes. |
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Leaves | cauline; sheaths usually shorter than the internodes, glabrous or sparsely pilose; collars glabrous; ligules less than 0.5 mm; blades 3-10 cm long, 1-2 mm wide, flat to folded basally, involute distally, scabridulous on both surfaces, occasionally sparsely pilose adaxially, light green. |
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Inflorescences | paniculate or racemose, 2-11 cm long, to 1 cm wide; nodes glabrous or strigillose; primary branches 1-2 cm, appressed, without axillary pulvini, with 1-2 spikelets. |
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Spikelets | partly overlapping, often in pairs, 1 spikelet subsessile, the other pedicellate. |
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Glumes | equal or subequal; lower glumes 3-6 mm; upper glumes 4-7 mm; lemmas 3-8 mm, sparsely appressed-pubescent; central awns 3-6 mm; lateral awns about 1 mm. |
1-veined, light gray to dark purplish or brownish; lower glumes 3-8(10) mm, from 1/2 as long as the upper glumes to nearly equaling them; upper glumes 4-13 mm; calluses 0.3-0.5 mm; lemmas 3-11 mm, light gray to purplish, frequently mottled, midveins scabrous, elsewhere glabrous, scabridulous, or sparsely appressed-puberulent, junction with the awns not evident; central awns 3-8 mm, coiled at the base, spreading distally; lateral awns 1-4 mm, straight, erect; anthers 3 and 2-3 mm, or 1 and about 0.25 mm. |
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Caryopses | 2-6 mm. |
light brown. |
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2n | = unknown. |
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Aristida dichotoma var. dichotoma |
Aristida dichotoma |
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Distribution |
AL; AR; CA; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MO; MS; NC; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WI; WV; ON |
AL; AR; CA; CO; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; SD; TN; TX; VA; VT; WI; WV; WY; ON
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Discussion | Aristida dichotoma grows in sandy fields and clearings, disturbed sites and sterile ground, pine woods, and on granitic outcrops of the United States and southern Ontario. The two varieties have similar ecological preferences and extensive overlap in their ranges, but var. curtissii is somewhat more western in its distribution. Aristida dichotoma is similar to A. basiramea, differing in its shorter lateral awns. Further study may show that the two should be treated as conspecific varieties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 25, p. 328. | FNA vol. 25, p. 328. | ||||
Parent taxa | ||||||
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Name authority | unknown | Michx. | ||||
Web links |
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