GrassBase - The Online World Grass Flora

Descriptions

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

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

Eragrostis exigua

HABIT Annual. Culms geniculately ascending; slender; 15–70 cm long; 1–3 -noded. Culm-internodes terete, or channelled. Lateral branches fastigiate. Leaf-sheaths wider than blade at the collar. Leaf-sheath oral hairs lacking. Ligule an eciliate membrane; 0.3–0.5 mm long; entire, or lacerate. Leaf-blades aciculate, or linear, or lanceolate; 2–5 mm wide. Leaf-blade surface scaberulous; rough adaxially. Leaf-blade margins cartilaginous; scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; elliptic; loose; 18–36 cm long; 3–7 cm wide; 0.66–0.8 of culm length. Primary panicle branches 1–3(–5) -nate; whorled at lower nodes; rebranched near base; 4–8 cm long. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1–2.5 mm long.

FERTILE SPIKELETS Spikelets comprising 3–7 fertile florets; with diminished florets at the apex. Spikelets oblong, or ovate; laterally compressed; 0.8–2 mm long; 0.5–0.8 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes straight; 0.1–0.2 mm long.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume oblong, or ovate; 0.4–0.6 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface asperulous; rough at apex. Lower glume apex emarginate, or obtuse. Upper glume oblong, or ovate; 0.4–0.6 mm long; 0.9 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume surface asperulous; rough at apex. Upper glume apex emarginate, or obtuse.

FLORETS Fertile lemma elliptic, or oblong; 0.5–0.7 mm long; membranous; keeled; 3 -veined. Lemma midvein thickened. Lemma lateral veins ribbed. Lemma apex truncate, or obtuse. Palea oblanceolate; with flaps as wide as body; 2 -veined. Palea keels falling well short of apex; smooth. Palea apex obtuse, or acute. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 2; 0.1–0.2 mm long.

FRUIT Caryopsis with adherent pericarp; ellipsoid, or obovoid; 0.3–0.5 mm long. Disseminule comprising a floret.

DISTRIBUTION Australasia: Australia.

NOTES Eragrostideae. Lazarides 1997.

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