Acrachne perrieri

HABIT Annual; caespitose. Culms geniculately ascending, or decumbent; 10–40 cm long. Ligule a ciliolate membrane; 1 mm long. Leaf-blades involute; 3–10 cm long; 0.5–1.5 mm wide. Leaf-blade surface pilose; sparsely hairy; hairy abaxially. Leaf-blade margins unthickened.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2–6; digitate, or borne along a central axis; unilateral; 1.5–6 cm long. Central inflorescence axis 0.5–3 cm long. Rhachis flattened; terminating in a sterile spikelet, or barren extension; extension subulate. Spikelet packing broadside to rhachis; regular; 1 -rowed.

Spikelets appressed; solitary. Fertile spikelets sessile.

STERILE SPIKELETS Apical sterile spikelets rudimentary; 1 in number.

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

GLUMES Glumes deciduous; similar; shorter than spikelet; recurved at apex. Lower glume lanceolate; 1.5 mm long; 0.7–0.8 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume apex acuminate; mucronate. Upper glume ovate; 2 mm long; 0.8–1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume apex setaceously attenuate.

FLORETS Fertile florets recurved at tip. Fertile lemma oblong; laterally compressed; oblong in profile; 2–2.5 mm long; membranous; keeled; 3 -veined. Lemma midvein scaberulous. Lemma lateral veins extending close to apex. Lemma apex entire; acuminate; awned; 1 -awned. Principal lemma awn 0.3–0.9 mm long overall. Palea bowed outwards; 0.8 length of lemma; 2 -veined. Palea keels scabrous. Palea apex acute. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 1 mm long. Stigmas 2.

FRUIT Caryopsis with free soft pericarp; ellipsoid; laterally compressed; estipitate; without sulcus; 0.5–0.7 mm long; smooth, or granular; apex unappendaged. Embryo 0.33 length of caryopsis. Hilum punctiform. Endosperm farinose. Disseminule comprising a caryopsis.

DISTRIBUTION Africa: western Indian ocean.

NOTES Eragrostideae. WDC.

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