Panicum scoparium

HABIT Perennial. Culms geniculately ascending; 80–150 cm long. Culm-internodes glandular (below nodes); distally pubescent. Culm-nodes pubescent. Lateral branches ample. Leaves basal and cauline; heterophyllous with a basal winter rosette. Leaf-sheaths pubescent. Ligule a fringe of hairs; 1–1.3 mm long. Leaf-blades lanceolate; 10–25 cm long; 8–18 mm wide; 13–30 mm wide in winter rosette. Leaf-blade venation distinct. Leaf-blade surface puberulous, or pubescent; hairy abaxially.

INFLORESCENCE Inflorescence a panicle; terminal and axillary.

Panicle open; ovate; 8–20 cm long. Panicle branches glandular.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong, or ovate; with obtuse base; dorsally compressed; compressed slightly; subacute; 2.2–2.8 mm long; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.25 length of spikelet; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume oblong; 1 length of spikelet; membranous; without keels; 7 -veined. Upper glume surface glabrous, or puberulous. Upper glume apex obtuse.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret similar to upper glume; oblong; 1 length of spikelet; membranous; 7 -veined; glabrous, or puberulous; obtuse. Fertile lemma oblong, or ovate; dorsally compressed; 2.2–2.8 mm long; indurate; without keel. Lemma margins involute. Lemma apex obtuse. Palea involute; indurate.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: north-central USA, northeast USA, south-central USA, and southeast USA. South America: Caribbean.

NOTES Paniceae. Gr Texas 1994.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.