Dichanthelium depauperatum (Muhl.) Gould (redirected from: Panicum depauperatum var. involutum)
Family: Poaceae
[Panicum depauperatum Muhl.,  more...]
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Plants cespitose. Basal rosettes poorly differentiated; blades similar in shape to the lower cauline blades, narrow, ascending. Culms 10-45 cm, erect to spreading, lower 4-10 internodes telescoped together, less than 2 cm, upper 2 internodes elongated; nodes bearded; internodes pubescent to subglabrous; fall phase a dense mass of erect blades and foreshortened branches that arise from the basal culm nodes, about 1/2 of the branches sterile, others with small, narrow, secondary panicles of 3-7 spikelets that remain enclosed within the sheaths. Cauline leaves 2-4; sheaths longer than the internodes, glabrous or densely ascending-pilose; ligules about 0.5 mm; blades 6-15 cm long, 1-4 mm wide, green to grayish-green, sometimes involute, glabrous or densely pilose, apices long-tapering, lower blades small to vestigial, upper 2 or 3 blades longer and stiffly erect. Primary panicles 3-6 cm long, 1.5-3 cm wide, usually long-exserted (sometimes contracted and remaining basal), with 7-25 spikelets. Spikelets 3.2-4.3 mm long, 1-1.7 mm wide, ellipsoid-pointed, glabrous or finely pubescent. Lower glumes 1.2-1.6 mm, narrowly triangular; upper glumes and lower lemmas exceeding the upper florets by 0.2-1 mm, forming a pointed beak, upper florets 1.9-3.1 mm, obovoid, minutely umbonate. 2n = 18.

Dichanthelium depauperatum grows in dry, open woodlands and open, disturbed areas, especially on sand. It is restricted to the Flora region. The primary panicles, which are rarely open-pollinated, are produced from May to early June; the secondary, cleistogamous panicles are produced from late June through July (rarely in fall). The species is linked with D. perlongum and D. linearifolium by occasional hybrids and hybrid derivatives. In the northern United States and Canada, 80-90% of the plants are glabrous and have been called Panicum depauperatum var. psilophyllum Fernald, Panicum depauperatum var. involutum (Torr.) Alph. Wood, or, if the primary panicles remain near the base, Panicum depauperatum forma cryptostachys Fernald; in this treatment, none of these are recognized as distinct taxonomic entities. The frequency of pilose plants increases southward, where some populations are entirely pilose.

Perennial herb, tufted 10 - 45 cm tall

Inflorescence: a terminal, branched arrangement of spikelets (panicle). Primary panicles atop the culms, 3 - 6 cm long, 1.5 - 3 cm wide, usually well-exserted, with seven to twenty-five spikelets. Secondary panicles (when present) atop the branches.

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

Culm: upright to spreading, 10 - 45 cm long, round in cross-section, hollow, nearly hairless to hairy. Lower internodes much shorter than the elongated upper two internodes. Fall phase a dense mass of upright leaf blades and shortened branches, arising from the basal nodes, producing sterile shoots and small secondary panicles which remain within the sheaths.

Spikelets: 3 - 4.5 mm long, 1 - 1.5 mm wide, ellipsoid with a pointed apex, sometimes finely hairy.

Basal leaves: in a rosette. Blades ascending, narrow, similar in shape to lower stem leaves.

Stem leaves: two to four, alternate, two-ranked. Sheaths longer than internodes, sometimes densely soft-hairy. Ligules about 0.5 mm long, composed of hairs. Blades stiff, upright, 6 - 15 cm long, 1 - 4 mm wide, (lower blades small to rudimentary), long-tapering to the tip, parallel-veined, sometimes densely soft-hairy.

Glumes:: Lower glumes 1 - 1.5 mm long, narrowly triangular. Upper glumes longer than upper florets by up to 1 mm, forming a beak.

Lemmas:: Lower lemmas similar to upper glumes, longer than upper florets by up to 1 mm, forming a beak. Upper lemmas longitudinally lined, shiny, with rolled-up margins above.

Paleas:: Lower paleas shorter than lower lemmas, thin. Upper paleas longitudinally lined.

Florets:: Upper florets bisexual, stalkless, 2 - 3 mm long, reverse egg-shaped with a protuberance at the apex, plump. Anthers three. Stigmas red.

Similar species: No information at this time.

Flowering: late May to late June

Habitat and ecology: Frequent in dry sandy Black Oak savannas. It is particularly common in the open sandy areas of the dune 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. Depauperatum means dwarved, starved, or depauperate.

Author: The Morton Arboretum

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

Infrequent in southern Indiana in open woodland on the crests of black oak, black and white oak, and chestnut oak ridges. In the northern part of the state it is local except in the dune area, where it is frequent in very sandy soil on open, wooded dunes or on sandy knolls and ridges.

Culms clustered, erect or nearly so, 1-4 dm, very slender, glabrous to puberulent; lvs bright green or blue-green, crowded toward the base, the basal and cauline similar, erect to narrowly ascending, glabrous to long-pilose (as also the sheaths), mostly 8-20 cm נ2-5 mm, the longest ones ca 20 times as long as wide; primary panicle narrow and relatively few-fld, with crooked, often short and appressed pedicels, 3-8 cm, eventually exsert, not much exceeding the lvs; spikelets glabrous or minutely hairy, ellipsoid, 2.7-4.1 mm, the first glume membranous, ovate or triangular, a third as long; second glume and sterile lemma sharply veined, pointed, projecting 0.5-1.5 mm beyond the fertile lemma; autumnal phase similar, the panicles small and usually concealed among the lvs near the base; 2n=18. Dry or sandy soil, commonly in open woods; N.S. and Que. to Minn., s. to Ga. and Tex. (Dichanthelium d.)

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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