Panicum lacustre

HABIT Perennial. Culms erect; 100–150 cm long; spongy; rooting from lower nodes. Culm-internodes distally glabrous. Leaf-sheaths glabrous on surface. Ligule a ciliate membrane; 1–2 mm long. Leaf-blades flat, or conduplicate; 15–30 cm long; 2 mm wide. Leaf-blade surface scaberulous; pilose; sparsely hairy; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 20–30 cm long; contracted about secondary branches. Primary panicle branches ascending; whorled at lower nodes. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1–2 mm long.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate, or oblong; dorsally compressed; acute; 2 mm long; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.25–0.33 length of spikelet; membranous; without keels. Lower glume apex obtuse. Upper glume elliptic; 1 length of spikelet; membranous; without keels; 5 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 7 -veined; acute. Fertile lemma elliptic; dorsally compressed; 1.8 mm long; indurate; without keel. Lemma margins involute. Lemma apex acute. Palea involute; indurate.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: southeast USA. South America: Caribbean.

NOTES Paniceae. Man Gr WI 1994.

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