Dichanthelium scabriusculum

(Elliott) Gould & C.A. Clark
Common names: Tall-swamp panicgrass
Endemic
Synonyms: Panicum scabriusculum var. cryptanthum Panicum scabriusculum Panicum cryptanthum
Treatment appears in FNA Volume 25. Treatment on page 418.

cPlants in large clumps, with rhizomes 3-5 mm thick. Basal rosettes well-differentiated; sheaths pubescent; blades lanceolate. Culms 70-150 cm, robust, purplish; nodes glabrous or puberulent; internodes scabridulous to almost glabrous; fall phase branching from the mid and upper culm nodes, developing numerous, well-separated, dense fascicles of many reduced blades and hidden secondary panicles. Cauline leaves 6-14; sheaths not overlapping, narrowing above midlength, sparsely to densely papillose-hispid, tops mottled with pale spots, margins ciliate, collars puberulent; ligules 0.5-1.2 mm, membranous; blades 12-25 cm long, 7-15 mm wide, linear, stiff, ascending to spreading, glabrous or sparsely pubescent, bases subcordate to constricted, margins scabridulous, apices long tapering, involute. Primary panicles 10-21 cm long, 6-13 cm wide, eventually well-exserted, with many spikelets; rachises and branches usually glabrous and mottled. Spikelets 2.2-2.8 mm long, 1-1.2 mm wide, ovoid-ellipsoid, often purplish, glabrous, rarely sparsely puberulent. Lower glumes 0.5-1 mm, acute; upper glumes and lower florets exceeding the upper florets, prominently 7-9-veined; lower florets sterile; upper florets acute to acuminate, with a minute tuft of hairs at the apices. 2n = 18.

Distribution

Md., N.J., Mass., Miss., Tex., La., R.I., Pa., Del., D.C., Ala., Tenn., N.C., S.C., Va., Ark., Ga., N.Y., Fla., Conn.

Discussion

Dichanthelium scabriusculum usually grows in wet, sandy, open sites, including shores, stream banks, swamps, and bogs. It is restricted to the eastern United States. The primary panicles develop from May to July, the secondary panicles, which are usually concealed within the sheaths, from July through November. Panicum aculeatum Hitchc. & Chase refers to what appear to be sterile hybrids with Dichanthelium clandestinum or robust subspecies of D. dichotomum, P. bennettense W.V. Br. to hybrids with D. aciculare.

Selected References

None.

Lower Taxa

None.

"usually distinctly longer and narrower" is not a number."decumbent" is not a number.

tapering +
anatomy +  and kranz +
Mary E. Barkworth +
(Elliott) Gould & C.A. Clark +
1 (?) +  and 3 (?) +
keeled +  and rounded +
well-differentiated +
pseudopetiolate +  and branching +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
subcordate +
constricted +
disarticulating +  and pseudopetiolate +
non-radiate +  and radiate +
fascicles +  and well-separated +
distinct +
12 cm120 mm <br />0.12 m <br /> (25 cm250 mm <br />0.25 m <br />) +
pubescent +  and glabrous +
many +  and numerous +
lanceolate +
reduced +
9 cm90 mm <br />0.09 m <br /> (25 cm250 mm <br />0.25 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
spikelike +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
not developed +
terete +  and compressed +
sometimes longer +
pale spots +  and mottled +
puberulent +  and papillose-hispid +
Tall-swamp panicgrass +
decumbent +  and sprawling +
spreading +, ascending +  and erect +
70 cm700 mm <br />0.7 m <br /> (150 cm1,500 mm <br />1.5 m <br />) +
Md. +, N.J. +, Mass. +, Miss. +, Tex. +, La. +, R.I. +, Pa. +, Del. +, D.C. +, Ala. +, Tenn. +, N.C. +, S.C. +, Va. +, Ark. +, Ga. +, N.Y. +, Fla. +  and Conn. +
capillary +
germination +
pistillate +  and staminate +
sometimes longer +
compressed +  and terete +
shorter or longer +
subtending +
unequal +
membranous +
uncinate +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Oval (?) +  and Round (?) +
bracteate +  and ebracteate +
scabridulous +
cauline +  and basal +
coriaceous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
membranous +
inconspicuous +
1/5 +  and 3/4 +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
pale spots +  and mottled +
puberulent +  and papillose-hispid +
scabridulous +
complex +  and simple +
concealed +  and prominent +
puberulent +  and glabrous +
2 +  and 1 +
subterranean +
dry +  and fleshy +
10 cm100 mm <br />0.1 m <br /> (21 cm210 mm <br />0.21 m <br />) +
6 cm60 mm <br />0.06 m <br /> (13 cm130 mm <br />0.13 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
not overlapping +
narrowing +
in triplets +  and paired +
0.22 cm2.2 mm <br />0.0022 m <br /> (0.28 cm2.8 mm <br />0.0028 m <br />) +
puberulent +  and glabrous +
unisexual +  and bisexual +
ovoid-ellipsoid +
0.22 cm2.2 mm <br />0.0022 m <br /> (0.36 cm3.6 mm <br />0.0036 m <br />) +
1mm +  and 1.2mm +
1 +  and 3 +
fused +  and free +
2 +  and 3 +
dome--shaped +  and triangular +
pubescent +  and papillose-hispid +
narrowed +
Panicum scabriusculum var. cryptanthum +, Panicum scabriusculum +  and Panicum cryptanthum +
Dichanthelium scabriusculum +
Dichanthelium sect. Clandestina +
species +
membranous +
pale spots +  and mottled +
midlength +
puberulent +  and papillose-hispid +
minute +
acute +  and acuminate +
chartaceous-indurate +
plant +  and cespitose +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +