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.

Eleusine tristachya

HABIT Perennial; short-lived; caespitose. Culms geniculately ascending, or decumbent; slender; 10–45 cm long. Culm-internodes elliptical in section. Leaves mostly basal. Leaf-sheaths keeled; outer margin glabrous. Ligule a ciliolate membrane. Leaf-blades 6–25 cm long; 1–4 mm wide.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2–3; digitate; linear, or oblong; unilateral; 1–4 cm long; 10–16 mm wide. Rhachis broadly winged; with rounded midrib. Spikelet packing broadside to rhachis.

Spikelets appressed; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 6–13 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 5–9 mm long; 4–6 mm wide; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet; similar to fertile lemma in texture. Lower glume lanceolate; 1.5–2 mm long; 0.5 length of upper glume; membranous; 1-keeled; 1–3 -veined. Lower glume apex acute. Upper glume elliptic; 3–4 mm long; 0.7–0.8 length of adjacent fertile lemma; membranous; 1-keeled; 5–7 -veined. Upper glume apex acute.

FLORETS Fertile lemma ovate; 4–5 mm long; membranous; keeled; 3 -veined (excluding subsidiaries). Lemma midvein with contiguous subsidiary veins (3-veined). Lemma apex acute. Palea 0.66 length of lemma; 2 -veined. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; cuneate; fleshy.

FRUIT Caryopsis with free soft pericarp; orbicular; isodiametric; trigonous; concealed by floret; 2 mm long; dark brown; rugose. Embryo 0.3–0.4 length of caryopsis. Hilum punctiform.

DISTRIBUTION Europe: northern, central, southwestern, and southeastern. Africa: Macaronesia and south. Asia-temperate: Caucasus. Australasia: Australia and New Zealand. South America: western South America, Brazil, and southern South America.

NOTES Eragrostideae. Fl Pat.

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