Gymnopogon ambiguus

(Michx.) Britton, Sterns & Poggenb.
Common names: Bearded skeletongrass
Treatment appears in FNA Volume 25. Treatment on page 231.

Plants cespitose, with a knotty base of short rhizomes. Culms 20-100 cm, suberect to spreading, stiff, simple to sparingly branched. Sheaths mostly glabrous, throats sometimes pubescent; collars conspicuously pubescent; ligules about 0.2 mm; blades (1.5) 2.5-12 cm long, (2) 5-10 (18) mm wide, somewhat cordate at the base, mostly glabrous, often pubescent near the basal margins. Panicles (6) 11.5-30 (35) cm; branches (3) 7-24 cm, stiffly spreading to somewhat reflexed, spikelet-bearing from the base, spikelets remote to slightly imbricate. Spikelets with 1 (2) florets. Glumes 4-7 mm; calluses bearded; bisexual lemmas 2.5-5 (6) mm, awns 4-12.2 mm; second florets often reduced to an obliquely inserted 2.4-6.2 mm awn; anthers 3, 0.8-1.2 mm. Caryopses 2-3 mm long, 0.2-0.5 mm wide. 2n = 40.

Distribution

Del., D.C., W.Va., Fla., N.J., Tex., La., Tenn., N.C., S.C., Pa., Va., Ala., Ark., Ill., Ga., Ind., Md., Kans., Okla., Ohio, Mo., Miss., Ky.

Discussion

Gymnopogon ambiguus grows in sandy pine woodlands of the southeastern United States, Haiti, and the Dominican Republic. It often grows with G. brevifolius, from which it differs in being more robust, having long, wider leaves, longer lemma awns, and, usually, having panicle branches that are spikelet-bearing to the base. Although spikelets of Gymnopogon ambiguus usually have only one floret, several plants from Texas have been found in which two florets per spikelet were the norm.

There is an 1853 collection of G. ambiguus supposedly from Dona Ana County, New Mexico, but there have been no recent collections from anywhere near there; it is possible that the locality data on the label are incorrect.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Gymnopogon ambiguus"
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
bidentate +
James P. Smith +  and Jr. +
(Michx.) Britton, Sterns & Poggenb. +
1 (?) +  and 3 (?) +
inserted +
multiple +, , +  and single +
0.24 cm2.4 mm <br />0.0024 m <br /> (0.62 cm6.2 mm <br />0.0062 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
not fused +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
not pseudopetiolate +
2.5 cm25 mm <br />0.025 m <br /> (12 cm120 mm <br />0.12 m <br />) +
pubescent +  and glabrous +
cordate +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
3 cm30 mm <br />0.03 m <br /> (?) +
reflexed;spreading to somewhat;spreading +
spikelike +
7 cm70 mm <br />0.07 m <br /> (24 cm240 mm <br />0.24 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
triangular +  and dome--shaped +
sometimes longer +
membranous +
Bearded skeletongrass +
simple +  and sparingly branched +
suberect +  and spreading +
20 cm200 mm <br />0.2 m <br /> (100 cm1,000 mm <br />1 m <br />) +
not woody +
Del. +, D.C. +, W.Va. +, Fla. +, N.J. +, Tex. +, La. +, Tenn. +, N.C. +, S.C. +, Pa. +, Va. +, Ala. +, Ark. +, Ill. +, Ga. +, Ind. +, Md. +, Kans. +, Okla. +, Ohio +, Mo. +, Miss. +  and Ky. +
not waisted +
capillary +
pistillate +  and staminate +
sometimes longer +
bisexual +  and sterile +
round +  and compressed +
reduced +
shorter or longer +
subtending +
acuminate +
subequal +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
uncinate +
paniculate +  and racemose +
hollow +  and solid +
not absent +
5-veined +, 7-13-veined +  and 1-3-veined +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
sometimes longer +
0.2 cm2 mm <br />0.002 m <br /> (?) +
membranous +
inconspicuous +
concealed +  and prominent +
2 +  and 1 +
divergent +  and arranged +
6 cm60 mm <br />0.06 m <br /> (?) +
11.5 cm115 mm <br />0.115 m <br /> (30 cm300 mm <br />0.3 m <br />) +
dry +  and fleshy +
spikelike +
remote +  and slightly imbricate +
compressed +
1 +  and 3 +
compound +  and simple +
2 (?) +  and 3 (?) +
Gramineae +
Gymnopogon ambiguus +
Gymnopogon +
species +
membranous +
7 (?) +  and 13 (?) +
plant +  and cespitose +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +