Culms to 100 cm, erect; nodes usually glabrous; internode s terete, usually glabrous, often slightly glaucous, sometimes olivaceous; fall phase with erect or decumbent culms, branching at the mid- and upper culm nodes, with numerous axillary branches, branches elongated and widely divergent, not forming fascicles. Cauline sheaths glabrous or the lowest sheaths sparsely pubescent; blades usually 5-8 mm wide, stiffly ascending or erect, often olivaceous or purplish abaxially, glabrous or sparsely pubescent basally. Spikelets 1.5-1.8 mm (seldom longer), broadly ellipsoid or obovoid, often purplish at the base, glabrous, obtuse to subacute. Upper florets 1.4-1.6 mm, broadly ellipsoid. 2n = unknown.

Dichanthelium dichotomum subsp. roanokense grows in marshes, wet pinelands, wet woods, and the borders of swamps. A relatively uncommon subspecies, it grows on the coastal plain from Delaware to southeastern Texas and in the West Indies. It is very similar to subsp. dichotomum and also exhibits traits of D. sphaerocarpon and D. erectifolium.

Perennial herb, tufted to 1 m tall

Inflorescence: a terminal, branched arrangement of spikelets (panicle). Primary panicles atop the culms, 3 - 12 cm long, long-exserted, wiry-branched. Secondary panicles (when present) atop the branches.

Fruit: a caryopsis, indehiscent, enclosed within the persistent lemma and palea.

Culm: decumbent to upright, to 1 m long, round in cross-section, often with a slightly waxy coating (glaucous), hollow. Fall phase with decumbent or upright culms, branching at the mid- and upper nodes.

Spikelets: often purplish basally, 1.5 - 2 mm long, broadly ellipsoid or reverse egg-shaped with a blunt to nearly pointed apex, prominently veined.

Basal leaves: in a rosette. Blades shortly egg-shaped to lance-shaped, distinct from stem blades.

Stem leaves: four to seven, alternate, two-ranked. Sheaths usually shorter than internodes, sometimes sparsely hairy on lowermost sheaths. Ligules about 0.5 mm long, composed of hairs. Blades thin, ascending to upright, often olive-colored or purplish basally, distinctly longer and narrower than basal leaves, 3.5 - 14 cm long, 5 - 8 mm wide, lance-shaped, parallel-veined, sometimes sparsely hairy basally.

Glumes:: Lower glumes usually less than one-third as long as spikelets, blunt to pointed. Upper glumes about as long as lower lemmas and upper florets, rounded to pointed at the apex.

Lemmas:: Lower lemmas similar to upper glumes. 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, about 1.5 mm long, less than 1 mm wide, broadly ellipsoid with a blunt to nearly pointed apex, plump. 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. Dichotomum means "forking in pairs." Roanokense means "of Roanoke Island" (in North Carolina).

Author: The Morton Arboretum