GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Paspalum rugulosum

HABIT Annual. Culms decumbent; 25–35 cm long. Culm-internodes terete, or semiterete; 3–13 cm long; distally glabrous. Culm-nodes brown; glabrous. Lateral branches ample. Leaf-sheaths 2.5–7 cm long; mostly shorter than adjacent culm internode; glabrous on surface; outer margin hairy. Ligule an eciliate membrane; 1.2–1.7 mm long; pubescent on abaxial surface. Collar glabrous. Leaf-blade base with a brief petiole-like connection to sheath; petiole pubescent. Leaf-blades lanceolate; 2–6.5 cm long; 4–10 mm wide. Leaf-blade midrib evident. Leaf-blade surface glabrous. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence composed of racemes. Peduncle 10–19 cm long; glabrous.

Racemes 6–10; borne along a central axis; ascending; unilateral; 1–3.5 cm long. Central inflorescence axis 4–7 cm long; glabrous. Rhachis narrowly winged; 0.5–0.8 mm wide; scabrous on surface; scabrous on margins; terminating in a sterile spikelet. Spikelet packing abaxial; 2 -rowed. Raceme-bases brief; pubescent.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.3–0.7 mm long; scaberulous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; subacute; 2.7–3 mm long; 0.9–1.1 mm wide; falling entire.

GLUMES Glumes one the lower absent or obscure; reaching apex of florets; thinner than fertile lemma. Upper glume elliptic; 1 length of spikelet; membranous; without keels; 3 -veined. Upper glume surface wrinkled (on margins).

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; acute. Fertile lemma elliptic; 2.3–2.4 mm long; 0.7 mm wide; indurate; yellow; shiny; without keel. Lemma surface smooth; glabrous. Lemma margins involute. Lemma apex acute. Palea involute; indurate.

FLOWER Lodicules 2; 0.3 mm long; truncate. Anthers 3; 1.5 mm long.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 1.8 mm long; pallid. Embryo 0.33 length of caryopsis. Hilum elliptic.

DISTRIBUTION South America: western South America.

NOTES Paniceae. Mor. & Zul. 2001.

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