Dichanthelium portoricense

(Desv. ex Ham.) B.E Hansen & Wunderlin
Common names: Blunt-glumed panicgrass
Synonyms: Panicum portoricense
Treatment appears in FNA Volume 25. Treatment on page 441.

Plants usually densely cespitose. Basal rosettes well-differenti¬ated; blades 1.5-6 cm, ovate to lanceolate. Culms 15-50 cm, slender, wiry; internodes olive green to purplish, densely puberulent or glabrous; fall phase spreading or decumbent, branching extensively from the lower and midculm nodes, producing numerous congested fascicles of reduced, flat or involute blades and reduced secondary panicles. Cauline leaves 4-7; sheaths much shorter than the internodes, densely crisp-puberulent, velvety-puberulent, or glabrous, often ciliate along the margins; ligules shorter than 0.5 mm; blades 2-7 cm long (seldom longer), 2.5-8 mm wide (rarely wider), spreading, firm, flat or slightly involute, without prominently raised veins, not longitudinally wrinkled, densely puberulent or glabrous abaxially, glabrous, sparsely puberulent, or pubescent adaxially, bases subcordate, with papillose-based cilia, margins often whitish and scabridulous. Primary panicles 2-7 cm long, 2/3 to nearly as wide as long, with relatively few spikelets, exserted; branches flexuous, spreading or reflexed, scabridulous to densely puberulent. Spikelets 1.5-2.6 mm, obovoid-pyriform, planoconvex in side view, puberulent, pubescent, or glabrous, attenuate basally, apices usually broadly rounded. Lower glumes 0.6-1.4 mm, thin, weakly-veined, attached about 0.2 mm below the upper glumes, clasping at the base; upper glumes as long as or slightly shorter than the lower lemmas; upper florets 1.4-2 mm, broadly ellipsoid, apices subacute, minutely puberulent. 2n = 18.

Discussion

Dichanthelium portoricense grows in sandy woods, low pinelands, savannahs, and coastal sand dunes, usually in moist places. Its range extends south from the Flora region into Mexico, the Caribbean, and Mesoamerica. It is a highly variable species with numerous intergrading forms, some possibly resulting from hybridization with other widespread species in the same region, such as D. sphaerocarpon and D. commutatum.

Selected References

None.

Key

1 Spikelets 1.8-2.6 mm long, usually densely pubescent or puberulent (rarely glabrous); cauline blades 4-7 cm long, 3.5-8 mm wide Dichanthelium portoricense subsp. patulum
1 Spikelets 1.5-2.0 mm long, puberulent to nearly glabrous; cauline blades 2-5 cm long, 2.5-4.5 mm wide Dichanthelium portoricense subsp. portoricense

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

puberulent +
subacute +  and rounded +
anatomy +  and kranz +
Mary E. Barkworth +
- Desv. ex Ham. B.E Hansen & Wunderlin +
1 - ? +  and 3 - ? +
keeled +  and rounded +
well-differentiated +
pseudopetiolate +  and branching +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
subcordate +
swelling +
disarticulating +  and pseudopetiolate +
distinct +
2 cm20 mm <br />0.02 m <br /> - 7 cm70 mm <br />0.07 m <br /> +
pubescent +, puberulent +, glabrous +  and , +
wrinkled +
involute +, flat +, ovate +  and lanceolate +
reduced +
1.5 cm15 mm <br />0.015 m <br /> - 6 cm60 mm <br />0.06 m <br /> +
0.25 cm2.5 mm <br />0.0025 m <br /> - 0.8 cm8 mm <br />0.008 m <br /> +
reflexed;spreading +
scabridulous +
spikelike +
0 cm0 mm <br />0 m <br /> - 1 cm10 mm <br />0.01 m <br /> +
not developed +
terete +  and compressed +
papillose-based +
sometimes longer +
Blunt-glumed panicgrass +
decumbent +  and sprawling +
spreading +, ascending +  and erect +
puberulent +
slender +
15 cm150 mm <br />0.15 m <br /> - 50 cm500 mm <br />0.5 m <br /> +
Minn. +, Conn. +, N.J. +, N.Y. +, Wash. +, Ala. +, Mich. +, N.C. +, Pa. +, Puerto Rico +, S.C. +, W.Va. +, Ark. +, Iowa +, Kans. +, Mo. +, N.Dak. +, Nebr. +, Okla. +, S.Dak. +, Del. +, D.C +, Wis. +, Alta. +, B.C. +, Man. +, N.B. +, Nfld. and Labr. - Labr. +, N.S. +, Ont. +, P.E.I. +, Que. +, Sask. +, Pacific Islands - Hawaii +, Md. +, Mass. +, Maine +, N.H. +, R.I. +, Vt. +, Fla. +, Wyo. +, Miss. +, Ariz. +, N.Mex. +, Tex. +, La. +, Ga. +, Tenn. +, Calif. +, Nev. +, Colo. +, Ill. +, Ind. +, Va. +, Idaho +, Ohio +, Utah +, Mont. +, Oreg. +  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 +
olive green +  and purplish +
glabrous +  and puberulent +
cauline +  and basal +
coriaceous +
0.5 cm5 mm <br />0.005 m <br /> - ? +
membranous +
inconspicuous +
1/5 +  and 3/4 +
acuminate +, acute +  and truncate +
0.2 cm2 mm <br />0.002 m <br /> - 0.06 cm0.6 mm <br />6.0e-4 m <br /> +
decumbent +  and spreading +
scabridulous +
complex +  and simple +
concealed +  and prominent +
2 +  and 1 +
subterranean +
dry +  and fleshy +
2 cm20 mm <br />0.02 m <br /> - 7 cm70 mm <br />0.07 m <br /> +
glabrous +, velvety-puberulent +  and crisp-puberulent +
in triplets +  and paired +
glabrous +, pubescent +  and puberulent +
unisexual +  and bisexual +
attenuate +, planoconvex +  and obovoid-pyriform +
0.15 cm1.5 mm <br />0.0015 m <br /> - 0.26 cm2.6 mm <br />0.0026 m <br /> +
1 +  and 3 +
fused +  and free +
2 +  and 3 +
dome--shaped +  and triangular +
Panicum portoricense +
Dichanthelium portoricense +
Dichanthelium sect. Lancearia +
species +
membranous +
0.14 cm1.4 mm <br />0.0014 m <br /> - 0.2 cm2 mm <br />0.002 m <br /> +
chartaceous-indurate +
plant +  and cespitose +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +