Dichanthelium commutatum subsp. commutatum

Plants with caudices. Culms more or less erect, usually glabrous, sometimes sparsely pubescent or puberulent. Basal blades large, usually 8-14 cm long, 7-22 mm wide. Cauline blades 3.5-8 times as long as wide, 6-25 mm wide, thin, ovate-lanceolate, green, sometimes glaucous, bases almost symmetrical. Spikelets 2.6-2.9 mm. Lower glumes about 1/4 as long as the spikelets; lower lemmas rounded apically.

Dichanthelium commutatum subsp. commutatum grows in wet to dry woodlands. Its range extends to South America.

Perennial herb, tufted 20 cm - 0.75 m tall Inflorescence: a terminal, branched arrangement of spikelets (panicle). Panicles atop the culms, open, 5 - 12 cm long, 3 - 10 cm wide, exserted. Secondary panicles (when present) atop the branches. Fruit: a caryopsis, indehiscent, enclosed within the persistent lemma and palea. Culm: more or less upright, often purplish, 20 cm - 0.75 m long, round in cross-section, hollow, sometimes sparsely hairy. Fall phase nearly upright, eventually sprawling, sparsely rebranching, producing leaf blades and secondary panicles that are smaller than those of the culms. Spikelets: purplish or yellowish green, 2.5 - 3 mm long, over 1 mm wide, narrowly ellipsoid, and hairy. Basal leaves: in a rosette. Blades 8 - 14 cm long, 7 - 22 mm wide, egg-shaped to lance-shaped, distinct from stem blades. Stem leaves: four to six, alternate, two-ranked. Sheaths purplish or olive-colored, usually shorter than internodes, often having a waxy coating (glaucous), sometimes minutely hairy, often fringed with hairs. Ligules less than 0.5 mm long, shortly membranous, fringed with hairs (hairs longer than membranous area). Blades thin, distinctly longer and narrower than basal leaves, to eight times as long as wide, 0.5 - 2.5 cm wide, egg- lance-shaped with a clasping, heart-shaped base, nearly symmetrical basally, many-veined, sometimes having a waxy coating (glaucous), sometimes minutely hairy, fringed with bumpy-based hairs. Glumes:: Lower glumes about one-fourth as long as spikelets. Upper glumes equal to or slightly shorter than spikelets, rounded to pointed at the apex. Lemmas:: Lower lemmas similar to upper glumes, equal to or slightly shorter than spikelets, rounded at the apex. Upper lemmas longitudinally lined, shiny, with rolled-up margins above. Paleas:: Lower paleas shorter than lower lemmas, thin. Upper paleas longitudinally lined. Florets:: Lower florets sterile. Upper florets bisexual, stalkless, plump, often bearing a tiny protuberance at the apex. Anthers three. Stigmas red.

Similar species: No information at this time.

Habitat and ecology: No information at this time.

Occurence in the Chicago region: native

Etymology: Dichanthelium comes from the Greek words di, meaning twice, and anth, meaning flowering, referring to plants that may have two flowering periods. Commutatum means changing.

Author: The Morton Arboretum

From Flora of Indiana (1940) by Charles C. Deam

This species is restricted usually to the high hills of the unglaciated area, although it is found in Jefferson County on the bluff of the Ohio River and in Jennings County on the sandstone outcrop along the Muscatatuck River near Vernon. It is rather local except in the knobstone, where it is frequent. My no. 27633 from Clark County is exceptional in that the whole plant is soft-pubescent, including both surfaces of the leaves.