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.

Dactyloctenium aegyptium

HABIT Annual; mat forming, or caespitose. Stolons present. Culms geniculately ascending, or decumbent; 5–70 cm long; rooting from lower nodes. Ligule a ciliolate membrane, or a ciliate membrane. Leaf-blades 3–25 cm long; 2.5–7.5 mm wide. Leaf-blade margins tuberculate-ciliate. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 3–9; digitate; spreading, or ascending; unilateral; 1.2–6.5 cm long. Rhachis deciduous from axis; flattened; terminating in a barren extension; extension bristle-like. Spikelet packing broadside to rhachis; crowded; regular; 2 -rowed.

Spikelets pectinate; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 3–4 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 3.5–4.5 mm long; breaking up at maturity; disarticulating above glumes but not between florets.

GLUMES Glumes persistent; dissimilar; shorter than spikelet. Lower glume ovate; 1.5–2.2 mm long; 1 length of upper glume; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acute. Upper glume oblong; 1.5–2.2 mm long; 0.5–0.6 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein smooth. Upper glume lateral veins absent. Upper glume apex obtuse; awned; 1 -awned. Upper glume awn subapical; 0.8–4 mm long.

FLORETS Fertile florets appressed to rhachilla. Fertile lemma gibbous; ovate in profile; 2.6–4 mm long; membranous; keeled; 3 -veined. Lemma midvein scaberulous. Lemma lateral veins obscure. Lemma apex acute, or cuspidate; muticous, or mucronate. Palea 1 length of lemma; 2 -veined. Palea keels wingless, or winged; narrowly winged. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; 0.25–0.8 mm long.

FRUIT Caryopsis with free soft pericarp; obovoid; 1 mm long; rugose.

DISTRIBUTION Europe: southeastern. Africa: north, Macaronesia, west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, south, middle Atlantic ocean, and western Indian ocean. Asia-temperate: western Asia, Arabia, China, and eastern Asia. Asia-tropical: India, Indo-China, Malesia, and Papuasia. Australasia: Australia. Pacific: southwestern, south-central, northwestern, and north-central. North America: northwest USA, north-central USA, northeast USA, southwest USA, south-central USA, southeast USA, and Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Eragrostideae. FTEA.

ADDITIONAL CHARACTERS Glume awn up to 2 length of body.

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