Paspalum rostratum

HABIT Annual; caespitose. Cataphylls evident. Rhizomes short. Culms erect; 60–82 cm long; 2 mm diam. Culm-internodes distally glabrous. Culm-nodes glabrous. Lateral branches ample; arising from upper culm. Leaf-sheaths longer than adjacent culm internode; glabrous on surface. Leaf-sheath auricles erect. Ligule an eciliate membrane; 0.3 mm long; pilose on abaxial surface; erose; obtuse. Leaf-blades spreading; flat, or conduplicate; 2.5–8.5 cm long; 0.5–1(–2) mm wide. Leaf-blade surface glabrous. Leaf-blade margins scaberulous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary. Peduncle 3–9 cm long; glabrous.

Racemes 1; single; unilateral; 1.5–4 cm long. Rhachis broadly winged; membranous; folded longitudinally to embrace spikelets; 3–4 mm wide; dark-coloured (green & purple); glabrous on surface; glabrous on margins; terminating in a barren extension; extension flattened. Spikelet packing crowded; 2 -rowed.

Spikelets solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate, or elliptic; dorsally compressed; 3–3.2 mm long; 0.8–1 mm wide; falling entire.

GLUMES Glumes one the lower absent or obscure; reaching apex of florets; thinner than fertile lemma. Upper glume elliptic; 3–3.2 mm long; 1 length of spikelet; membranous; without keels; 3 -veined. Upper glume surface pilose; hairy at base. Upper glume margins ciliate. Upper glume hairs 2 mm long. Upper glume apex with a unilateral tooth; attenuate; mucronate, or awned; 1 -awned. Upper glume awn 1–1.8 mm long.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; elliptic; 2.8 mm long; 1 length of spikelet; membranous; 3 -veined; pubescent; hairy at base; ciliate on margins; fringed above; mucronate, or awned. Awn of lower sterile floret 0.8–1.4 mm long. Fertile lemma elliptic; 2–2.1 mm long; 0.5–0.6 mm wide; membranous; pallid; without keel. Lemma margins convolute; covering most of palea. Lemma apex rostrate; pubescent. Palea involute; membranous.

FLOWER Anthers 3; 2 mm long; orange.

FRUIT Caryopsis with adherent pericarp; oblong; 0.9–1.1 mm long. Hilum elliptic. Disseminule comprising a spikelet. Secondary disseminule a floret.

DISTRIBUTION South America: Brazil.

NOTES Paniceae. Ramos, Valls & Oliviera 2012.

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