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corkscrew threeawn

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.

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.

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.

Spikelets

appressed.

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.

Caryopses

3-4 mm, somewhat lustrous, chestnut-colored.

2n

= unknown.

Aristida rhizomopbora

Aristida gyrans

Distribution
from FNA
FL; GA
[BONAP county map]
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.)

Source FNA vol. 25, p. 340.
Parent taxa Poaceae > subfam. Aristidoideae > tribe Aristideae > Aristida
Sibling taxa
A. adscensionis, A. arizonica, A. basiramea, A. californica, A. condensata, A. desmantha, A. dichotoma, A. divaricata, A. floridana, A. gypsophila, A. gyrans, A. havardii, A. lanosa, A. longespica, A. mohrii, A. oligantha, A. palustris, A. pansa, A. patula, A. purpurascens, A. purpurea, A. ramosissima, A. rhizomophora, A. schiedeana, A. simpliciflora, A. spiciformis, A. stricta, A. ternipes, A. tuberculosa
A. adscensionis, A. arizonica, A. basiramea, A. californica, A. condensata, A. desmantha, A. dichotoma, A. divaricata, A. floridana, A. gypsophila, A. havardii, A. lanosa, A. longespica, A. mohrii, A. oligantha, A. palustris, A. pansa, A. patula, A. purpurascens, A. purpurea, A. ramosissima, A. rhizomophora, A. schiedeana, A. simpliciflora, A. spiciformis, A. stricta, A. ternipes, A. tuberculosa
Name authority Chapm.
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