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 orthoclada

HABIT Perennial; caespitose. Glands annular. Culms erect, or geniculately ascending; slender; 20–80 cm long; 0.4–1 mm diam. Culm-nodes glabrous. Leaf-sheaths glabrous on surface, or pubescent. Leaf-sheath oral hairs ciliate. Ligule a fringe of hairs; 0.3 mm long. Leaf-blades 3–15 cm long; 1.5–3 mm wide. Leaf-blade surface glabrous, or pilose; sparsely hairy.

INFLORESCENCE Inflorescence a panicle.

Panicle open; oblong, or ovate; effuse; 6–23 cm long; 3–10 cm wide. Primary panicle branches whorled at lower nodes. Panicle branches glandular (in axils); bearded in axils.

Spikelets solitary. Fertile spikelets sessile, or pedicelled. Pedicels scabrous.

FERTILE SPIKELETS Spikelets comprising 5–9 fertile florets; with diminished florets at the apex. Spikelets elliptic, or oblong; laterally compressed; 5.5–6.5 mm long; 1–1.2 mm wide; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes deciduous; similar; shorter than spikelet. Lower glume lanceolate; 1.2–2 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 1.2–2 mm long; 0.75–1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 1.7–2 mm long; membranous; yellow, or purple; keeled; 3 -veined. Lemma midvein scabrous. Lemma lateral veins prominent. Lemma apex acute. Palea 1.4 mm long. Palea keels ciliolate; with hairs 0.1–0.2 mm long. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 0.3 mm long.

FRUIT Caryopsis with adherent pericarp; oblong, or ovoid; 0.6–0.8 mm long.

DISTRIBUTION South America: western South America and southern South America.

NOTES Eragrostideae. Fl Entre Rios 1995.

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