Paspalum biaristatum

HABIT Perennial; caespitose. Rhizomes short; knotty. Culms geniculately ascending; 73–125 cm long; 6–9 -noded. Culm-internodes hollow; smooth, or scaberulous. Culm-nodes brown; glabrous, or pubescent. Lateral branches lacking, or sparse. Leaves cauline. Leaf-sheaths without keel; striately veined; glabrous on surface, or hirsute; with tubercle-based hairs; outer margin hairy. Ligule a ciliate membrane; 1–1.5 mm long. Leaf-blades 7.2–19.3 cm long; 1.2–5 mm wide. Leaf-blade midrib prominent beneath. Leaf-blade surface hirsute; with tubercle-based hairs. Leaf-blade margins ciliate. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes (1–)2–4(–7); borne along a central axis; arcuate; unilateral; 3–8 cm long. Central inflorescence axis 4–5.8 cm long. Rhachis broadly winged; folded longitudinally to embrace spikelets; 9–14 mm wide; light-coloured (pallid & green); ciliate on margins; terminating in a barren extension; extension flattened. Spikelet packing abaxial. Raceme-bases brief; pubescent.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.3–0.5 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate, or elliptic; dorsally compressed; 3.8–4.5 mm long; 0.4–0.5 mm wide; falling entire.

GLUMES Glumes one the lower absent or obscure; reaching apex of florets; thinner than fertile lemma. Upper glume ovate; 3.8–4.5 mm long; 1 length of spikelet; membranous; without keels; 3 -veined. Upper glume surface pubescent; hairy below. Upper glume margins ciliate. Upper glume hairs 1.7–2.2 mm long. Upper glume awned; 1 -awned. Upper glume awn 4–7 mm long.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 3 -veined; pubescent; hairy below; ciliate on margins; bearing hairs 1.7–2.2 mm long; awned. Awn of lower sterile floret 3.8–4.5 mm long. Fertile lemma elliptic; 3.5–3.7 mm long; coriaceous; pallid; without keel; 5 -veined. Lemma lateral veins obscure. Lemma margins involute; ciliate; hairy above. Lemma hairs 0.5–1.2 mm long. Palea involute; 3.2–3.4 mm long; coriaceous. Palea apex papillose.

FLOWER Lodicules absent. Anthers 3; 2–2.2 mm long; yellow.

FRUIT Caryopsis with adherent pericarp; 1.2–1.5 mm long. Embryo 0.4–0.5 length of caryopsis. Hilum punctiform.

DISTRIBUTION South America: Brazil.

NOTES Paniceae. Filg & Dav 1994.

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