Echinochloa walteri

HABIT Annual; caespitose. Culms erect, or geniculately ascending; 100–200 cm long. Culm-nodes glabrous, or pubescent. Leaf-sheaths hirsute, or hispid; with tubercle-based hairs. Ligule absent. Leaf-blades 8–30 mm wide. Leaf-blade surface glabrous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 10–25; borne along a central axis; unilateral; 2–17 cm long; with branchlets at base of longer racemes. Central inflorescence axis 10–40 cm long. Rhachis subterete; with scattered hairs, or glabrous on surface. Spikelet packing crowded; 4 -rowed.

Spikelets in pairs. Fertile spikelets pedicelled; subequal. Pedicels unequal.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; gibbous; cuspidate; 3–5 mm long; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; clasping; 0.33–0.75 length of spikelet; without keels. Lower glume surface scabrous. Lower glume apex cuspidate. Upper glume ovate; 1 length of spikelet; membranous; without keels; 5 -veined. Upper glume surface spinose; glabrous, or hispid. Upper glume apex cuspidate.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; membranous; 5 -veined; scabrous; hispidulous; cuspidate; awned. Awn of lower sterile floret 15–60 mm long. Fertile lemma oblong; gibbous; 3–4 mm long; indurate; much thinner above; shiny; without keel. Lemma margins involute. Lemma apex acute; laterally pinched. Palea reflexed at apex; indurate.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: eastern Canada, north-central USA, northeast USA, south-central USA, southeast USA, and Mexico. South America: Mesoamericana, Caribbean, western South America, and Brazil.

NOTES Paniceae. Gr Texas 1994.

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