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.

Tragus berteronianus

HABIT Annual; caespitose. Culms erect, or geniculately ascending; 5–60 cm long. Ligule a fringe of hairs. Leaf-blades 1–6 cm long; 2–5 mm wide. Leaf-blade margins ciliate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes numerous; borne along a central axis; closely spaced; in a multilateral false spike; spreading; oblong; 0.3–0.7 cm long; bearing few fertile spikelets; bearing 2 fertile spikelets on each. Central inflorescence axis 2–15 cm long. Rhachis evident; deciduous from axis; subterete. Raceme-bases filiform; 0.5 mm long.

Spikelets in pairs. Fertile spikelets sessile; 2 in the cluster; the upper smaller.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 2–3 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes one the lower absent or obscure; exceeding apex of florets; firmer than fertile lemma. Upper glume ovate; 2–3 mm long; 1.2 length of adjacent fertile lemma; membranous; without keels; 5 -veined. Upper glume lateral veins thickened; ribbed. Upper glume surface with hooked spines (often bulbous); rough on veins. Upper glume apex acute.

FLORETS Fertile lemma ovate; dorsally compressed; 1.5–2.5 mm long; membranous; without keel; 3 -veined. Lemma surface puberulous. Lemma apex acuminate. Palea 2 -veined.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 0.4–0.6 mm long.

FRUIT Caryopsis with adherent pericarp; ellipsoid; dorsally compressed; biconvex; 1–2 mm long. Embryo 0.5 length of caryopsis.

DISTRIBUTION Africa: north, west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, south, and western Indian ocean. Asia-temperate: western Asia, Arabia, and China. Asia-tropical: India. Pacific: north-central. North America: southwest USA, south-central USA, and Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Cynodonteae. FTEA.

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