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Descriptions

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

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

Acrachne henrardiana

HABIT Annual; caespitose. Culms geniculately ascending, or decumbent; 10–40 cm long; rooting from lower nodes. Ligule an eciliate membrane; 2 mm long. Leaf-blades 10–20 cm long; 3–7 mm wide; flaccid. Leaf-blade surface pilose; sparsely hairy; hairy abaxially. Leaf-blade margins cartilaginous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 6–15; borne along a central axis; in several whorls; unilateral; 1–1.5 cm long. Central inflorescence axis 4–8 cm long. Rhachis angular; terminating in a sterile spikelet. Spikelet packing broadside to rhachis; regular; 2 -rowed.

Spikelets solitary. Fertile spikelets sessile.

STERILE SPIKELETS Apical sterile spikelets rudimentary; 1 in number.

FERTILE SPIKELETS Spikelets comprising 2–6 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 2–3 mm long; 2 mm wide; breaking up at maturity; rhachilla persistent; retaining paleas. Rhachilla internodes obscured by lemmas.

GLUMES Glumes deciduous; similar; shorter than spikelet. Lower glume ovate; 1.5 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume oblong; 1.5 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume apex acuminate; awned; 1 -awned. Upper glume awn 1 mm long.

FLORETS Fertile florets recurved at tip. Fertile lemma ovate; laterally compressed; ovate in profile; 1.5 mm long; membranous; keeled; 3 -veined. Lemma midvein scaberulous. Lemma lateral veins stopping well short of apex. Lemma apex entire; acute; awned; 1 -awned. Principal lemma awn 0.5 mm long overall. Palea ovate; bowed outwards; 0.8 length of lemma; 2 -veined. Palea keels scabrous. Apical sterile florets resembling fertile though underdeveloped.

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

FRUIT Caryopsis with free soft pericarp; ellipsoid; isodiametric; biconvex; estipitate; sulcate on hilar side; 0.6 mm long; rugose; apex unappendaged. Embryo 0.3–0.5 length of caryopsis. Hilum punctiform. Endosperm farinose. Disseminule comprising a caryopsis.

DISTRIBUTION Asia-tropical: India.

NOTES Eragrostideae. Lorch.

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