Aristida gyrans

Chapm.
Common names: Corkscrew threeawn
Endemic
Treatment appears in FNA Volume 25. Treatment on page 340.
Revision as of 02:55, 30 July 2020 by imported>Volume Importer
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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, some¬what 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.

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.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Aristida gyrans"
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
Kelly W. Allred +
Chapm. +
not disarticulating +  and not coiled +
1 (?) +  and 3 (?) +
tan;dark brownish or purplish +
straight +
ascending +  and spreading +
not evident +
subequal +
0.8 cm8 mm <br />0.008 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
keeled +  and rounded +
coiled +, disarticulating +  and twisted +
pale green +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
straight +
5 cm50 mm <br />0.05 m <br /> (15 cm150 mm <br />0.15 m <br />) +
flat +, folded +  and involute +
0 cm0 mm <br />0 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
spikelike +
well-developed +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
chestnut-colored +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
non-radiate +  and radiate +
Corkscrew threeawn +
20 cm200 mm <br />0.2 m <br /> (65 cm650 mm <br />0.65 m <br />) +
geniculate +
10 cm100 mm <br />0.1 m <br /> (150 cm1,500 mm <br />1.5 m <br />) +
not woody +
0.1 cm1 mm <br />0.001 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Fla. +  and Ga. +
large +  and small +
capillary +
germination +
pistillate +  and staminate +
sometimes longer +
compressed +  and terete +
subtending +
awned +  and acuminate +
unequal +
racemose +  and paniculate +
10 cm100 mm <br />0.1 m <br /> (?) +  and 30 cm300 mm <br />0.3 m <br /> (?) +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
scabridulous +
fusiform +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
coriaceous +
indistinguishable +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
inconspicuous +
0.6 cm6 mm <br />0.006 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
concealed +  and prominent +
2 +  and 1 +
concealing +
0 +  and 1/2 +
dry +  and fleshy +
divaricate +  and divergent +
ascending;usually appressed;ascending +
3 cm30 mm <br />0.03 m <br /> (5 cm50 mm <br />0.05 m <br />) +
not prolonged +
1 (?) +  and Anatomy (?) +
1 +  and 3 +
triangular +  and dome--shaped +
2 (?) +  and 3 (?) +
Gramineae +
Aristida gyrans +
Aristida +
species +
membranous +
0.9 cm9 mm <br />0.009 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
plant +  and cespitose +
aquatic +  and terrestrial +