Limnodea arkansana

HABIT Annual. Culms 20–60 cm long. Ligule an eciliate membrane; lacerate. Leaf-blades 3–12 cm long; 2–8 mm wide.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; 5–20 cm long. Primary panicle branches bearing spikelets almost to the base.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 3.5–4 mm long; falling entire.

GLUMES Glumes similar; reaching apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of upper glume; coriaceous; without keels; 3–5 -veined. Lower glume surface scabrous. Lower glume apex acute. Upper glume lanceolate; 1 length of adjacent fertile lemma; coriaceous; without keels; 3–5 -veined. Upper glume surface scabrous. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 3.5–4 mm long; cartilaginous; keeled; lightly keeled; 3 -veined. Lemma margins covering most of palea. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn subapical; geniculate; 8–11 mm long overall; with twisted column. Palea 0.7 length of lemma; 2 -veined. Rhachilla extension 0.15–0.25 length of fertile floret.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp. Endosperm liquid.

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

NOTES Aveneae. Gould.

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