Dichanthelium strigosum

(Muhl. ex Elliott) Freckmann
Common names: Cushion-tufted panicgrass
Synonyms: Panicum strigosum
Treatment appears in FNA Volume 25. Treatment on page 446.

Plants densely cespitose. Basal rosettes poorly differentiated; blades 1-5 cm, lanceolate, grading into the cauline blades. Culms 5-45 cm, slender, erect or spreading; from a dense tuft of predominantly basal leaves, lower internodes short, upper 3-5 internodes elongate; nodes glabrous or bearded; internodes glabrous or pilose; fall phase with spreading culms and branches arising from near the bases forming a dense, flat tuft. Cauline leaves 2-4; lower cauline sheaths longer than the internodes, mostly glabrous or pilose with ascending hairs, margins finely ciliate; ligules 0.2-2 mm, at low magnification appearing to be membranous and ciliate, at high magnification evidently of hairs that are coherent at the base; blades 1.5-6 cm long, 3-8 mm wide, lanceolate, glabrous or softly pilose, margins with prominent papillose-based cilia, at least basally. Primary panicles short- to long-exserted; rachises and branches often pilose. Spikelets 1.1-2.1 mm, obovoid to broadly ellipsoid, glabrous or pubescent, hairs not papillose-based. Lower glumes 1/3 - 1/2 as long as the spikelets, acute to obtuse; upper florets 0.8-1.7 mm, ellipsoid, subacute.

Distribution

Puerto Rico, Va., Ga., Tex., La., Ala., Tenn., N.C., S.C., Miss., Fla.

Discussion

Dichanthelium strigosum extends from the southeastern Flora region south into Mexico, the Caribbean, and into northern South America.

The primary panicles are briefly open-pollinated in April or May; the secondary panicles, which are produced from May through November, are cleistogamous. The three subspecies are mostly sympatric and sometimes grow together, with occasional intergradation.

Selected References

None.

Key

1 Spikelets pubescent, broadly ellipsoid, 1.6-2.1 mm long; lower glumes about 1/2 as long as the spikelets; blades glabrous Dichanthelium strigosum subsp. leucoblepharis
1 Spikelets glabrous, obovoid, 1.1-1.8 mm long; lower glumes about 1/3 as long as the spikelets; blades pilose or glabrous. > 2
2 Blades pilose; spikelets 1.1-1.6 mm long Dichanthelium strigosum subsp. strigosum
2 Blades glabrous or sparsely pilose near the base; spikelets 1.4-1.8 mm long Dichanthelium strigosum subsp. glabrescens