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Descriptions

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

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

Tragus racemosus

HABIT Annual; caespitose. Culms 3–25 cm long. Ligule a fringe of hairs. Leaf-blades 1–4 cm long; 1–3 mm wide.

INFLORESCENCE Inflorescence composed of racemes; subtended by an inflated leaf-sheath.

Racemes numerous; borne along a central axis; closely spaced; in a multilateral false spike; spreading; cuneate; 0.4–0.9 cm long; bearing few fertile spikelets; bearing 2–4 fertile spikelets on each. Central inflorescence axis (2–)5–7.5 cm long. Rhachis evident; deciduous from axis; subterete; terminating in a barren extension; extension subulate. Raceme-bases linear; 0.5–1.5 mm long; pubescent; hairy in axils.

Spikelets solitary. Fertile spikelets sessile.

STERILE SPIKELETS Apical sterile spikelets rudimentary; 1–2 in number (per raceme).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 4–5.5 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume ovate; 0.5–1 mm long; 0.1–0.2 length of upper glume; hyaline; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume elliptic; 4–5.5 mm long; 1.1 length of adjacent fertile lemma; membranous; without keels; 7 -veined. Upper glume lateral veins thickened; ribbed. Upper glume surface with hooked spines; rough on veins. Upper glume apex acuminate.

FLORETS Fertile lemma elliptic; dorsally compressed; 3.5–5 mm long; membranous; without keel; 3 -veined. Lemma apex acuminate. Palea 2 -veined.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3.

FRUIT Caryopsis with adherent pericarp; ellipsoid; dorsally compressed; biconvex.

DISTRIBUTION Europe: central, southwestern, southeastern, and eastern. Africa: north, Macaronesia, west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, and south. Asia-temperate: Soviet Middle Asia, Caucasus, western Asia, Arabia, and China. North America: northeast USA, southwest USA, south-central USA, and southeast USA. South America: western South America and southern South America.

NOTES Cynodonteae. WDC.

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