Dichanthelium dichotomum subsp. lucidum

Culms occasionally more than 60 cm, very slender, weak; nodes usually glabrous; internodes often flattened, green, glabrous; fall phase with reclining or decumbent culms and numerous axillary branches, branches elongated and widely divergent, not forming fascicles. Cauline sheaths usually shorter than the internodes, glabrous; blades slightly smaller than those of the other subspecies, ascending or spreading, often lustrous, bright green, glabrous throughout. Primary panicles slightly smaller and with fewer spikelets than in the other subspecies (particularly subsp. dichotomum, which it closely resembles). Spikelets 1.8-2.3 mm, ellipsoid, usually glabrous, obtuse to subacute; upper florets 1.7-2 mm. 2n = unknown.

Dichanthelium dichotomum subsp. lucidum grows in wet woods, the margins of cypress swamps, sphagnum bogs, and other similar, wet habitats. It is primarily a species of the coastal plain, ranging from New Jersey to Florida, southeastern Texas, and up the Mississippi embayment to western Tennessee and, as a disjunct, on the Indiana Dunes of Lake Michigan.

Perennial herb, tufted 20 cm - 0.6 m tall Inflorescence: a terminal, branched arrangement of spikelets (panicle). Primary panicles atop the culms, a bit smaller than those of the other subspecies, 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, 20 cm - 0.6 m or more long, very slender, hollow. Internodes green, often flattened. Fall phase with decumbent or reclining culms, many-branched with long, widely diverging branches. Spikelets: about 2 mm long, ellipsoid 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. Ligules about 0.5 mm long, composed of hairs. Blades thin, spreading to ascending, distinctly longer and narrower than basal leaves, a bit smaller than those of the other subspecies, lance-shaped, parallel-veined. 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, 1.5 - 2 mm long, less than 1 mm wide, ellipsoid with a blunt to nearly pointed apex, plump. Anthers three. Stigmas red.

Similar species: No information at this time.

Flowering: June

Habitat and ecology: Rare in the Chicago Region, and known only from Porter County, Indiana. There it grows in wet woods. It has also been found in a boggy depression in a sedge meadow.

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." Lucidum means shining.

Author: The Morton Arboretum

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

Our Indiana record is based upon Umbach's specimen no. 4962 collected at Dune Park, Porter County, which is deposited in the U. S. National Herbarium. Pepoon reports it also from the same area. It is an inhabitant of wet woods and sphagnum marshes.

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Indiana Coefficient of Conservatism: C = 10

Wetland Indicator Status: FAC