Plants cespitose, with caudices. Basal rosettes well-differentiated;
blades 1.5-6 cm, ovate to lanceolate, soft, glabrous. Culms 10-40
cm tall, 0.2-0.8 (1.6) mm thick, weak, erect or reclining; nodes usually
glabrous, sometimes sparsely bearded; internodes usually glabrous, occasionally
sparsely pubescent; fall phase with spreading culms, sparingly branched,
branching mostly from the midculm nodes, occasionally producing small fascicles
of leafy branchlets. Cauline leaves 4-9; sheaths much shorter
than the internodes, prominently veined, glabrous or sparsely pilose and ciliate,
particularly at the top; ligules 0.2-1.8 mm, often more than 1 mm, of
hairs, without adjacent pseudoligules; blades 1.5-3.5 cm long (seldom
longer), 1.5-4 mm wide, all similar in size, thin, spreading or reflexed, abaxial
surfaces puberulent, at least apically, or sparsely pilose, adaxial surfaces
glabrous or sparsely pilose, at least basally, bases abruptly and strongly constricted,
occasionally ciliate, margins entire or faintly scabridulous, rarely white-cartilaginous.
Primary panicles 1.5-4 cm, nearly as wide as long, long-exserted; branches
wiry, mostly spreading, minutely scabridulous. Spikelets 1.2-1.5 mm,
ellipsoid to obovoid, yellow-green to purplish, puberulent or glabrous, subacute
or obtuse. Lower glumes seldom more than 1/4 as long as the spikelets,
acute or obtuse; upper glumes usually slightly shorter than the lower
lemmas and upper florets, not strongly veined; upper florets 1.1-1.4
mm long, less than 1 mm wide, ellipsoid, acute. 2n = 18.
Dichanthelium ensifolium grows in wet to moist, sandy pinelands, savannahs,
and bogs, often on Sphagnum mats, primarily on the coastal plain. It
extends south into Mesoamerica, and has been reported from Venezuela. Occasional
specimens grade towards the larger D. tenue, and are usually found on somewhat drier sites. It also resembles D.
chamaelonche, but that species is usually more densely cespitose, has
slightly smaller, glabrous spikelets, and generally occupies drier, disturbed
sites.
The two subspecies are sympatric, often growing together at
the same sites.
Culms tufted, very slender, erect or reclining, 1.5-4 dm; sheaths glabrous or minutely ciliate; ligule a band of hairs to 0.5 mm; cauline lvs few and distant, spreading or reflexed, 1-5 cm נ2-5 mm, with thin green margins, much constricted at base, glabrous above or puberulent at base, glabrous to puberulent beneath; primary panicle soon long-exsert, 2-6 cm, ovoid with short, spreading branches and few spikelets; spikelets glabrous or minutely hairy, ellipsoid or obovoid, somewhat pointed, 0.9-1.5 mm; first glume a third to two-fifths as long, ovate, obtusely pointed; second glume and sterile lemma shorter than the fr; autumnal phase copiously and often fastigiately branched from the lower nodes, sometimes forming dense mats, the blades 1-2 cm, the panicles 1 cm, equaling or barely exceeding the lvs; 2n=18. Bogs and wet woods, or rarely in dry pine-land; coastal plain from s. N.J. to La. (P. chamaelonche; Dichanthelium dichotomum var. e.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.