Paspalum costaricense

HABIT Perennial; caespitose. Rootstock evident. Culms 30–75 cm long; 2–3 mm diam. Culm-internodes hollow; distally glabrous. Culm-nodes glabrous. Lateral branches lacking. Leaf-sheaths glabrous on surface; outer margin hairy. Ligule an eciliate membrane; 3–5 mm long; brown. Leaf-blades filiform; 10–18 cm long; 10–30 mm wide. Leaf-blade midrib conspicuous. Leaf-blade surface glabrous. Leaf-blade margins ciliate. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 5–7; borne along a central axis; unilateral; 4–7 cm long. Central inflorescence axis 2–6 cm long. Rhachis wingless; flattened; 0.6–1 mm wide. Spikelet packing 4 -rowed. Raceme-bases brief; hirsute.

Spikelets in pairs. Fertile spikelets pedicelled. Pedicels 0.5–1.5 mm long.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic, or obovate; dorsally compressed; subacute; 2.4–2.8 mm long; falling entire.

GLUMES Glumes one the lower absent or obscure; reaching apex of florets; thinner than fertile lemma. Upper glume ovate; 1 length of spikelet; membranous; dark brown, or purple; without keels; 3–5 -veined. Upper glume surface puberulous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 3–5 -veined; puberulous. Fertile lemma elliptic, or obovate; 2.2–2.5 mm long; indurate; yellow; without keel. Lemma surface striate. Lemma margins involute. Palea involute; indurate.

FLOWER Anthers 3; 0.9–1 mm long; purple.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 1.9 mm long.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Paniceae. Fl Costaric 1994.

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