Plants densely cespitose. Basal rosettes poorly differentiated;
blades ovate to lanceolate. Culms 15-55 cm, slender, erect or radiating
from a large tuft of predominantly basal leaves, lower internodes short, upper
3-5 internodes elongate; nodes bearded with soft, spreading or retrorse
hairs; internodes glabrous; fall phase branching extensively from
the basal nodes, forming a dense cushion that overwinters. Cauline leaves
2-4; sheaths usually longer than the internodes, pilose, hairs to 4 mm,
retrorse or spreading; ligules 0.2-1 mm, at low magnification appearing
to be membranous and ciliate, at high magnification evidently of hairs that are
coherent at the base; blades 4-17 cm long, 4-12 mmwide, lanceolate, at least
3/4 as long as the basal blades, spreading to suberect, thin, soft, lax, yellowish-green,
nearly glabrous or densely pilose on 1 or both surfaces, margins usually finely
short-ciliate, at least on the basal 1/2, cilia not papillose-based. Primary
panicles 4-12 cm long, 3-8 cm wide, well-exserted; secondary panicles
more compact, usually not exserted above the crowded basal leaves; rachises
and branches wiry, spreading or deflexed, often pilose. Spikelets
1.7-2.3 mm long, 1-1.2 mm wide, broadly ovate or oblong-obovoid, with papillose-based
hairs, obtuse. Lower glumes 1/4-1/3 as long as the spikelets, broadly deltoid;
upper glumes and lower lemmas subequal, usually fully covering the
upper florets; upper florets 1.5-1.8 mm long, 1-1.2 mm wide, broadly ellipsoid
or obovoid, minutely umbonate. 2n = 18.
Dichanthelium laxiflorum is a widespread, common species that grows in mesic
deciduous woods, and occasionally in drier, more open woodlands. Its range extends
south from the Flora region into Mexico. The density of the pubescence
on the blade surfaces varies greatly.
The primary (spring) panicles are apparently chasmogamous; the secondary panicles
are largely cleistogamous and are produced from late spring to winter.
Culms clustered, 2-5 dm, simple or branched at the base only, the nodes bearded with soft, spreading hairs; sheaths pilose with spreading or more often retrorse hairs to 4 mm; ligule an entire or minutely fringed rim less than 0.5 mm, or obsolete; basal lvs numerous, relatively long and soft, similar to and only slightly if at all shorter than the soft, yellowish-green lower cauline lvs; blades 8-15 cm נ5-10 mm, sparsely pilose to glabrous on both sides, finely ciliate to glabrous on the margins, the uppermost one generally at least three-fourths as long as the basal ones; primary panicle 6-10 cm, its branches spreading, sparsely pilose to glabrous; spikelets soft-hairy, oblong-obovoid, 1.7-2.3 mm, obtuse; first glume broadly deltoid, a fourth to a third as long; second glume and sterile lemma soon separated and surpassed by the white or pale stramineous fr; autumnal phase basally branched, the blades scarcely reduced, much exceeding the small infls; 2n=18. Woods; Md. to s. Ind. and s. Mo., s. to Fla. and Tex. (P. xalapense; Dichanthelium l.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.