Dichanthelium linearifolium (Scribn. ex Nash) Gould
Source: USDA Plants_111306
Family: Poaceae
Dichanthelium linearifolium image

Plants cespitose. Basal rosettes poorly differentiated; blades similar in shape to the lower cauline blades, narrow, ascending. Culms 10-50 cm, very slender, erect to drooping, lower 3-8 internodes telescoped together, less than 2 cm, upper 2 internodes elongated; nodes bearded; internodes pubescent to almost glabrous; fall phase developing a dense mass of erect blades and foreshortened branches arising from the basal nodes, terminating in small, narrow secondary panicles that are enclosed within the sheaths, with 6-15 spikelets. Cauline leaves 2-4; sheaths longer than the internodes, glabrous or pilose with dense, fine, papillose-based hairs; ligules about 0.5 mm; blades 5-20 cm long, 2-5 mm wide, stiffly ascending to erect, green to grayish-green, glabrous or densely pilose, apices long-tapering, lower blades shorter than the upper 2 or 3 blades. Primary panicles 4-10 cm long, 2-6 cm wide, long-exserted, with 12-70 spikelets; branches and pedicels spreading. Spikelets 2-3.2 mm long, 0.8-1.4 mm wide, ellipsoid, not turgid, sparsely pubescent. Lower glumes 0.6-1.1 mm, ovate-triangular; upper glumes and lower lemmas exceeding the upper florets by about 0.2 mm before flowering, subequal in fruit, slightly pointed at maturity, upper florets 1.7-2.3 mm, ovoid-ellipsoid, minutely umbonate. 2n = 18.

Dichanthelium linearifolium grows in dry, open woodlands, rock outcroppings, and sandy areas. It is restricted to the Flora region. The primary panicles are briefly open-pollinated, produced from May to early June; the secondary panicles are cleistogamous, produced from late June through July (rarely in fall). Plants in the northern United States and Canada tend to be shorter and more spreading, subglabrous, and to have spikelets 2-2.6 mm long; they have been called Panicum werneri Scribn., but do not merit taxonomic recognition. In the southwestern part of its range, especially in the Ozarks, most plants of D. linearifolium are tall, erect, densely pilose, with very elongated blades and spikelets often 2.6-3 mm long; they may hybridize with D. perlongum.

Perennial herb, tufted 10 cm - 0.5 m tall Inflorescence: a terminal, branched arrangement of spikelets (panicle). Primary panicles atop the culms, 4 - 10 cm long, 2 - 6 cm wide, well-exserted, with twelve to seventy spikelets. Secondary panicles (when present) atop the branches. Fruit: a caryopsis, indehiscent, enclosed within the persistent lemma and palea. Culm: upright to drooping, 10 cm - 0.5 m long, very thin, round in cross-section, hollow, nearly hairless to hairy. Lower internodes much shorter than the elongated upper two internodes. Nodes bearded. Fall phase a dense mass of upright leaf blades and shortened branches, arising from the basal nodes, producing small secondary panicles which remain within the sheaths. Spikelets: 2 - 3 mm long, 0.5 - 1.5 mm wide, ellipsoid, sparsely 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 softly hairy with fine, bumpy-based hairs. Ligules about 0.5 mm long, composed of hairs. Blades stiff, upright to ascending, 5 - 20 cm long, 2 - 5 mm wide, long-tapering to the tip, parallel-veined, sometimes densely soft-hairy. Glumes:: Lower glumes 0.5 - 1 mm long, egg-shaped to triangular. Upper glumes more or less equal to upper florets, slightly pointed at the apex. Lemmas:: Lower lemmas similar to upper glumes, more or less equal to upper florets, slightly pointed 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:: Upper florets bisexual, stalkless, 1.5 - 2 mm long, egg-shaped to ellipsoid with a minute protuberance at the apex, plump. Anthers three. Stigmas red.

Similar species: No information at this time.

Flowering: late May to mid-June

Habitat and ecology: Local in open sandy soil near Lake Michigan.

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. Linearifolium means linear-leaved.

Author: The Morton Arboretum

From Flora of Indiana (1940) by Charles C. Deam
Infrequent in the unglaciated area of the southern part of the state and in sandy habitats of the lake area. In the south it is found in open woodland on the crests of ridges, and in the lake area it is found in dry, sandy soil on open dunes, sandy knolls, and sandy ridges.
Vegetatively much like no. 17 [Panicum depauperatum Muhl.], avg somewhat taller and eventually more branched; primary panicle more numerously fld, usually much surpassing the lvs, at maturity open, the longest pedicels 8-18 mm; spikelets ellipsoid, 1.7-3.1 mm, glabrous to pilose; second glume and sterile lemma blunt, about equaling the fr; 2n=18. Dry or stony soil, open woods, and banks; N.S. and Que. to Minn., s. to Ga. and Tex. (P. werneri; Dichanthelium l.) Occasional plants intermediate toward no. 17, called P. perlongum Nash, may be of hybrid origin.

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

©The New York Botanical Garden. All rights reserved. Used by permission.