Echinochloa helodes

HABIT Perennial. Rhizomes elongated. Culms decumbent; 30–130 cm long; 3–4 mm diam. Culm-nodes pubescent. Leaf-sheaths glabrous on surface. Ligule a fringe of hairs; 1–4 mm long. Leaf-blades 7.5–30 cm long; 5–12 mm wide. Leaf-blade surface glabrous. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 5–10; borne along a central axis; appressed; unilateral; 2–4 cm long. Central inflorescence axis 6–20 cm long. Rhachis subterete; scabrous on margins. Spikelet packing 4 -rowed.

Spikelets in pairs. Fertile spikelets pedicelled; subequal. Pedicels unequal; 1–6 mm long; tip discoid.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; cuspidate; 6–7 mm long; 1.7–2.2 mm wide; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; clasping; 4.5–5 mm long; 0.75 length of spikelet; without keels; 7 -veined. Lower glume surface scabrous; rough on veins. Lower glume apex cuspidate. Upper glume elliptic; 1 length of spikelet; membranous; without keels; 9 -veined. Upper glume surface hispidulous. Upper glume apex acuminate; awned; 1 -awned. Upper glume awn 2–5 mm long.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 9 -veined; hispidulous; acuminate; awned. Awn of lower sterile floret 5–15 mm long. Fertile lemma ovate; 5–5.8 mm long; indurate; much thinner above; shiny; without keel. Lemma margins involute. Lemma apex rostrate; laterally pinched. Palea reflexed at apex; indurate.

FLOWER Anthers 3; 3.5–4 mm long; red.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: southern South America.

NOTES Paniceae. Fl Entrerios 1994.

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