Dichanthelium acuminatum subsp. acuminatum
Family: Poaceae
Tapered Witch Grass,  more...
[Dichanthelium auburne (Ashe) Mohlenbr.,  more...]
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Perennial herb, tufted 15 cm - 1 m tall

Inflorescence: a terminal, branched arrangement of spikelets (panicle). Primary panicles atop the culms, stalked (stalk over 8 cm long), often open, rather dense, 3 - 12 cm long, one-fourth to three-fourths as wide as long, well-exserted. Secondary panicles (when present) atop the branches.

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

Culm: upright or ascending or decumbent, 15 cm - 1 m long, round in cross-section, hollow, densely velvety-hairy. Nodes sometimes swollen, densely hairy with a hairless ring below. Fall phase much-branched from the mid-culm nodes and forming fan-shaped clusters of branches.

Spikelets: 1.5 - 2 mm long, broadly ellipsoid or reverse egg-shaped with a blunt to nearly pointed apex, variously hairy.

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 (about half as long at mid-culm), densely soft-hairy (hairs under 3 mm long). Ligules 1 - 5 mm long, composed of hairs. Blades lax or firm, spreading to ascending, distinctly longer and narrower than basal leaves, 6 - 12 cm long, to 10 mm wide, lance-shaped with a rounded or almost heart-shaped base, parallel-veined, softly hairy, with a marginal fringe of bumpy-based hairs (at least basally).

Glumes:: Lower glumes usually one-fourth to one-half as long as spikelets, blunt to pointed at the apex. Upper glumes 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 - 1.5 mm long, 0.5 - 1 mm wide, ellipsoid with a blunt to pointed apex, plump. Anthers three. Stigmas red.

Similar species: No information at this time.

Flowering: late June to July

Habitat and ecology: Occasional in a variety of moist to dry, peaty or sandy habitats, mostly in the eastern sector of the Chicago Region.

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. Acuminatum means "tapering to a long point."

Author: The Morton Arboretum

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

Our only specimen is one collected by Hill, July 8, 1913, in dry sand by a woods road at Dune Park, Porter County. It is Hill's no. 7 and is deposited in the herbarium of the University of Illinois. I have a duplicate of this number.