Author
Jennifer Bodin
Common Name(s)
openflower rosette grass; soft-tufted panicgrass
Ecology
Dichanthelium laxiflorum is a widespread, common species that grows in mesic deciduous woods, and occasionally in drier, more open woodlands.
Electronic links
Clayton, W.D., Harman, K.T. and Williamson, H. (2006 onwards). GrassBase - The Online World Grass Flora. http://www.kew.org/data/grasses-db.html. [accessed 08 November 2006; 15:30 GMT]
Species treatment as Panicum laxiflorum: http://www.kew.org/data/grasses-db/www/imp07082.htm
USDA, NRCS. 2007. The PLANTS Database (http://plants.usda.gov, 18 April 2007).
Species Profile: http://plants.usda.gov/java/profile?symbol=DILA9
Grass Manual on the Web (Flora North America): http://herbarium.usu.edu/webmanual/
Family
Poaceae (Gramineae) grass family
Flowering period
Late winter to spring; late summer and fall.
Inflorescences
Inflorescence of spring phase a panicle. Panicle open; pyramidal; loose; 7–12 cm long; bearing few spikelets; axis hirsute; branches hirsute; spikelets spreading; solitary; fertile spikelets pedicelled. Summer/autumn phase more compact, usually not exserted above the crowded basal leaves; rachises and branches wiry, spreading or deflexed, often pilose.
Leaves
Cauline leaves 2-4; sheaths usually longer than the internodes, pilose, hairs to 4 mm, retrorse or spreading;
ligules 0.2-1 mm, at low magnification appearing to be membranous and ciliate, at high magnification evidently of hairs that are coherent at the base.
blades 4-17 cm long, 4-12 mmwide, lanceolate, at least 3/4 as long as the basal blades, spreading to suberect, thin, soft, lax, yellowish-green, nearly glabrous or densely pilose on 1 or both surfaces, margins usually finely short-ciliate, at least on the basal 1/2, cilia not papillose-based
Plant and Stem Features
Perennial, basal rosettes poorly differentiated;
Culms 15-55 cm, slender, erect or radiating from a large tuft of predominantly basal leaves, lower internodes short, upper 3-5 internodes elongate; nodes bearded with soft, spreading or retrorse hairs.
References
Clayton, W.D., Harman, K.T. and Williamson, H. (2006 onwards). GrassBase - The Online World Grass Flora. http://www.kew.org/data/grasses-db.html. [accessed 08 November 2006; 15:30 GMT]
Freckmann, R. W. and M. G. Lelong. 2003. Dichanthelium (Hitchc. & Chase) Gould. In: Flora of
Grass Manual on the Web (Flora North America): http://herbarium.usu.edu/webmanual/
USDA, NRCS. 2007. The PLANTS Database (http://plants.usda.gov, 18 April 2007).
Species name
Dichanthelium laxiflorum (Lam.) Gould
Spikelets
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rachilla extension; dorsally compressed; obtuse; 1.7-2.3 mm long, 1-1.2 mm wide, broadly ovate or oblong-obovoid, with papillose-based hairs, obtuse; spikelets falling entire.
Glumes dissimilar; reaching apex of florets; thinner than fertile lemma.
Lower glumes 1/4-1/3 as long as the spikelets, broadly deltoid to ovate; 0.5 mm long; membranous; without keels; 1-veined; lateral veins absent; apex acute.
Upper glumes and lower lemmas subequal, usually fully covering the upper florets;
Florets: Basal sterile florets barren; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 1.7–2.3 mm long; 1 times length of spikelet; membranous; 5-veined; pubescent; obtuse. Upper florets 1.5-1.8 mm long, 1-1.2 mm wide, broadly ellipsoid or obovoid, minutely umbonate. Fertile lemma elliptic; dorsally compressed; 1.5–2 mm long; indurate; shiny; without keel. Lemma margins involute. Palea involute; indurate. Anthers 3.
Synonyms
Panicum laxiflorum Lam.
Panicum laxiflorum Lam. var. strictirameum (A.S. Hitchc. & Chase) Fern.
Panicum xalapense Kunth