Paspalum vexillarium

HABIT Perennial; caespitose. Butt sheaths persistent and investing base of culm; with compacted dead sheaths. Culms erect; 60–75 cm long; 1 mm diam.; 3–7 -noded. Culm-internodes distally glabrous, or pubescent. Culm-nodes bearded. Lateral branches sparse; arising from lower culm. Leaves without demarcation between sheath and blade. Leaf-sheaths 1–11 cm long; keeled; striately veined; glabrous on surface, or hirsute. Ligule an eciliate membrane; 0.3 mm long; erose; obtuse. Leaf-blades flat, or involute; 15–25 cm long; 3–5(–10) mm wide. Leaf-blade surface glabrous, or hirsute; hairy adaxially. Leaf-blade margins scabrous; ciliate; hairy at base. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes. Peduncle 9–17 cm long; pubescent above.

Racemes 2–6; paired, or borne along a central axis; unilateral; 2–6 cm long. Central inflorescence axis 2–6 cm long; tip subulate. Rhachis broadly winged; membranous; folded longitudinally to embrace spikelets; 5–12 mm wide; light-coloured (green, orange & purple); terminating in a barren extension; extension flattened. Spikelet packing abaxial; crowded; 2 -rowed. Raceme-bases pubescent.

Spikelets solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; plano-convex; 2–2.9 mm long; falling entire.

GLUMES Glumes one the lower absent or obscure; reaching apex of florets; thinner than fertile lemma. Upper glume ovate; 2–2.9 mm long; 1 length of spikelet; membranous; pallid, or light brown; without keels; 3 -veined. Upper glume surface pilose; hairy at apex; with tubercle-based hairs; with basal tufts of hair (2 tufts near apex). Upper glume hairs 2–2.5 mm long. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong, or obovate; 1.6–2.3 mm long; 0.8 length of spikelet; membranous; 2 -veined; prominently veined; concave across back; pilose; hairy at apex; with marginal tufts of hair; 2 hair tufts in all (near apex); obtuse. Fertile lemma elliptic, or ovate; 2–2.1 mm long; 0.7–0.8 mm wide; coriaceous; pallid; without keel; 3 -veined. Lemma lateral veins obscure. Lemma surface puberulous; hairy above. Lemma margins involute. Lemma apex acuminate. Palea involute; coriaceous. Palea surface puberulous; hairy above.

FLOWER Lodicules absent. Anthers 3; 2.2 mm long; yellow.

FRUIT Caryopsis with adherent pericarp; obovoid; dorsally compressed; plano-convex; 1.1 mm long. Hilum elliptic; 0.25 length of caryopsis.

DISTRIBUTION South America: Brazil.

NOTES Paniceae. Rua et al 2009.

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