Dichanthelium dichotomum subsp. roanokense

(Ashe) Freckmann & Lelong
Synonyms: Panicum roanokense Panicum hirstii Panicum dichotomum var. roanokense
Treatment appears in FNA Volume 25. Treatment on page 434.

Culms to 100 cm, erect; nodes usually glabrous; internodes terete, usually glabrous, often slightly glaucous, sometimes olivaceous; fall phase with erect or decumbent culms, branching at the mid and upper culm nodes, with numerous axillary branches, branches elongated and widely divergent, not forming fascicles. Cauline sheaths glabrous or the lowest sheaths sparsely pubescent; blades usually 5-8 mm wide, stiffly ascending or erect, often olivaceous or purplish abaxially, glabrous or sparsely pubescent basally. Spikelets 1.5-1.8 mm (seldom longer), broadly ellipsoid or obovoid, often purplish at the base, glabrous, obtuse to subacute. Upper florets 1.4-1.6 mm, broadly ellipsoid. 2n = unknown.

Discussion

Dichanthelium dichotomum subsp. roanokense grows in marshes, wet pinelands, wet woods, and the borders of swamps. A relatively uncommon subspecies, it grows on the coastal plain from Delaware to south¬eastern Texas and in the West Indies.

It is very similar to subsp. dichotomum and also exhibits traits of Dichanthelium sphaerocarpon and D. erectifolium.

Selected References

None.

Lower Taxa

None.

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

rounded +  and attenuate +
anatomy +  and kranz +
Mary E. Barkworth +
(Ashe) Freckmann & Lelong +
1 (?) +  and 3 (?) +
keeled +  and rounded +
well-differentiated +
pseudopetiolate +  and branching +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
constricted +
disarticulating +  and pseudopetiolate +
non-radiate +  and radiate +
purplish +  and olivaceous +
distinct +
3.5 cm35 mm <br />0.035 m <br /> (14 cm140 mm <br />0.14 m <br />) +
pubescent +  and glabrous +
subcordate +, ovate +  and lanceolate +
0.5 cm5 mm <br />0.005 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
not fascicles +  and divergent +
ascending;spreading +
scabridulous +
spikelike +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
fascicles +  and divergent +
not developed +
terete +  and compressed +
sometimes longer +
Large (?) +  and Small (?) +
decumbent +  and sprawling +
decumbent +  and erect +
geniculate +
0 cm0 mm <br />0 m <br /> (100 cm1,000 mm <br />1 m <br />) +
Conn. +, N.J. +, N.Y. +, Va. +, Del. +, D.C. +, Wis. +, W.Va. +, N.B. +, Ont. +, Mass. +, Maine +, N.H. +, R.I. +, Vt. +, Fla. +, Tex. +, La. +, Tenn. +, N.C. +, S.C. +, Pa. +, Puerto Rico +, Ark. +, Iowa +, Md. +, Ala. +, Ill. +, Ga. +, Ind. +, Okla. +, Ohio +, Mo. +, Minn. +, Mich. +, Miss. +  and Ky. +
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 +
solid +  and hollow +
glaucous +  and glabrous +
fascicles +  and divergent +
fascicles +  and divergent +
cauline +  and basal +
coriaceous +
1 cm10 mm <br />0.01 m <br /> (?) +
membranous +
inconspicuous +
obtuse +  and acute +
pubescent +  and glabrous +
glabrous +  and ciliate +
complex +  and simple +
rebranched +  and branched +
concealed +  and prominent +
2 +  and 1 +
subterranean +
dry +  and fleshy +
3 cm30 mm <br />0.03 m <br /> (12 cm120 mm <br />0.12 m <br />) +
in triplets +  and paired +
many +  and few +
unisexual +  and bisexual +
obtuse +  and subacute +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
1 +  and 3 +
fused +  and free +
2 +  and 3 +
dome--shaped +  and triangular +
Panicum roanokense +, Panicum hirstii +  and Panicum dichotomum var. roanokense +
Dichanthelium dichotomum subsp. roanokense +
Dichanthelium dichotomum +
subspecies +
membranous +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.14 cm1.4 mm <br />0.0014 m <br /> (0.16 cm1.6 mm <br />0.0016 m <br />) +
0 cm0 mm <br />0 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
usually slightly shorter +
chartaceous-indurate +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +