Eragrostis riobrancensis

HABIT Perennial. Culms geniculately ascending; 30–70 cm long. Lateral branches lacking. Ligule a ciliate membrane; 0.2–0.3 mm long. Leaf-blades persistent, or deciduous at the ligule; flat, or involute; 4–8 cm long; 1–2.5 mm wide. Leaf-blade surface glabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle; exserted, or embraced at base by subtending leaf.

Panicle open; ovate; 7–11 cm long; 3–6 cm wide. Primary panicle branches 3–5 in number; ascending; 1–3.5 cm long. Panicle branches scaberulous; glabrous in axils.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 7–17 fertile florets; with diminished florets at the apex. Spikelets linear, or oblong; laterally compressed; 5.5–14 mm long; 1.5–2.5 mm wide; breaking up at maturity; rhachilla persistent; retaining paleas; tough throughout, or fragile above.

GLUMES Glumes deciduous; similar; shorter than spikelet. Lower glume ovate; 0.5–1.5 mm long; 0.3–0.6 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume ovate; 1.8–2.5 mm long; 0.7–0.8 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 2.2–3 mm long; membranous; keeled; 3 -veined. Lemma apex acute. Palea bowed outwards; 1.5–2 mm long. Palea keels winged; narrowly winged; scaberulous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 2; 0.2–0.35 mm long; purple.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 0.7–0.8 mm long.

CLEISTOGENES AND VIVIPARY Cleistogenes present; in upper sheaths.

DISTRIBUTION South America: northern South America and Brazil.

NOTES Eragrostideae. Judz 1995.

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