Aristida rhizomopbora |
Aristida gyrans |
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corkscrew threeawn |
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Habit | Plants perennial; tightly cespitose, bases often bleached, without rhizomes. | |
Culms | 20-65 cm tall, 1-4 mm thick at the base, erect, rarely geniculate at the base, unbranched; internodes often in a sequence of 2 short and 1 long. |
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Leaves | mostly basal; sheaths usually shorter than the internodes, glabrous, remaining intact at maturity; collars glabrous; ligules 0.2-0.3 mm; blades (3)5-15 cm long, to 1 mm wide, involute, rarely loosely folded or flat, somewhat stiff and arcuate, bases glabrous abaxially, pale green. |
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Inflorescences | paniculate or racemose, 10-30 cm long, 1-2 cm wide, slender, lax; primary branches 3-5 cm, loosely appressed, without axillary pulvini, with 2-5 spikelets. |
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Spikelets | appressed. |
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Glumes | usually unequal, 1-veined, acuminate or awned, awns to 4 mm, tan to dark brownish or purplish; Lower glumes 6-9(11) mm; upper glumes 9-12 mm; calluses 1-2 mm; lemmas 5-7 mm, glabrous, brownish, without a column, the junction with the awns not evident; awns 8-15 mm, subequal, loosely spirally contorted, but not coiled, just above the base, ascending to spreading distally, not disarticulating at maturity; anthers 3, 1-1.5 mm, brownish. |
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Caryopses | 3-4 mm, somewhat lustrous, chestnut-colored. |
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2n | = unknown. |
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Aristida rhizomopbora |
Aristida gyrans |
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Distribution |
FL; GA |
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Discussion | Aristida gyrans is endemic to the southeastern United States, growing in sandy pine woods and oak scrub. It differs from other species in the genus by its combination of narrow blades, unequal glumes, long calluses, and contorted awns. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 25, p. 340. | |
Parent taxa | ||
Sibling taxa | ||
Name authority | Chapm. | |
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