GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Eragrostis potamophila

HABIT Perennial. Cataphylls evident. Butt sheaths glossy; glabrous. Culms 60–90 cm long; 5 -noded. Culm-internodes eglandular; ridged. Leaf-sheaths tight; eglandular; glabrous on surface. Leaf-sheath oral hairs scanty; 2–3.5 mm long. Ligule a fringe of hairs; 0.1–0.2 mm long. Leaf-blades curled; flat, or involute, or convolute; 15–35 cm long; 4–9 mm wide. Leaf-blade surface scabrous; rough adaxially; glabrous; hairless throughout, or except near base. Leaf-blade margins cartilaginous; eglandular; scabrous.

INFLORESCENCE Inflorescence a panicle. Peduncle eglandular.

Panicle open; ovate; loose, or effuse; 20–36.5 cm long; 5–12 cm wide. Primary panicle branches spreading, or drooping; 7–15 cm long. Panicle axis eglandular. Panicle branches flexible; eglandular.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 2–20 mm long; eglandular.

FERTILE SPIKELETS Spikelets comprising 9–55 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; 4.2–25 mm long; 1–2 mm wide; breaking up at maturity; rhachilla persistent; retaining paleas. Rhachilla internodes thickened; zig-zag; 0.5–0.6 mm long; obscured by lemmas.

GLUMES Glumes deciduous; similar; shorter than spikelet. Lower glume lanceolate; 0.5–1.3 mm long; 0.5–0.75 length of upper glume; membranous; without keels, or 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute, or acuminate. Upper glume lanceolate; 1–1.8 mm long; 0.8–0.9 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute, or acuminate.

FLORETS Fertile lemma elliptic, or ovate; 1.3–1.7 mm long; membranous; keeled; 3 -veined. Lemma lateral veins close to margins. Lemma surface smooth, or granulose. Lemma apex obtuse. Palea oblong, or oblanceolate; with flaps narrower than body; 1 length of lemma; hyaline; 2 -veined. Palea keels thickened; scaberulous. Palea apex emarginate, or obtuse; glabrous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers (2–)3; 0.3–0.5 mm long.

FRUIT Caryopsis with adherent pericarp, or tardily free pericarp; oblong; isodiametric; 0.5–0.7 mm long; red.

DISTRIBUTION Australasia: Australia.

NOTES Eragrostideae. Lazarides 1997.

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