Panicum plenum

HABIT Perennial; caespitose. Rhizomes elongated. Culms geniculately ascending; 50–100 cm long. Culm-internodes elliptical in section. Culm-nodes glabrous. Leaf-sheaths mostly shorter than adjacent culm internode; keeled; glabrous on surface, or pubescent. Ligule a ciliolate membrane; 0.5–2 mm long. Leaf-blades 20–35 cm long; 2–17 mm wide. Leaf-blade surface glabrous, or pilose; sparsely hairy; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 12–50 cm long. Primary panicle branches spreading; not whorled, or whorled at lower nodes.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.2–4 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 2.5–3.5 mm long; 1.2 mm wide; falling entire.

GLUMES Glumes reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.33–0.5 length of spikelet; membranous; without keels; 3 -veined. Lower glume apex acute. Upper glume elliptic; 1 length of spikelet; membranous; without keels; 5 -veined. Upper glume apex acute.

FLORETS Basal sterile florets male, or barren; with palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 5 -veined; acute. Fertile lemma elliptic; dorsally compressed; 2.9–3 mm long; indurate; pallid; without keel. Lemma surface rugulose. Lemma margins involute. Lemma apex acute; pubescent. Palea involute; indurate.

DISTRIBUTION North America: southwest USA, south-central USA, and Mexico.

NOTES Paniceae. Fl N Amer 2007.

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