GrassBase - The Online World Grass Flora

Descriptions

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

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

Paspalum volcanense

HABIT Perennial; caespitose. Rhizomes elongated; scaly; glabrous. Basal innovations extravaginal. Culms 45–60 cm long; 2.4–3 mm diam.; 3–6 -noded. Culm-internodes 2.5–15 cm long; yellow; striate. Culm-nodes swollen; brown; glabrous, or pubescent. Leaf-sheaths 9.5–22 cm long; keeled; striately veined; glabrous on surface, or pilose; outer margin hairy. Ligule an eciliate membrane; 2–3 mm long; brown; truncate. Leaf-blades lanceolate; 12–22 cm long; 7–13 mm wide. Leaf-blade surface glabrous, or pilose; hairy abaxially; with tubercle-based hairs. Leaf-blade margins tuberculate-ciliate. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence composed of racemes. Peduncle 9–25 cm long; glabrous.

Racemes 4–19; borne along a central axis; unilateral; 4–9 cm long. Central inflorescence axis 6–10 cm long; glabrous. Rhachis angular; 1–1.6 mm wide; ciliate on margins; terminating in a barren extension. Spikelet packing 4 -rowed. Raceme-bases pilose.

Spikelets in pairs. Fertile spikelets pedicelled. Pedicels oblong; unequal; 0.5–1.3 mm long; glabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; concavo-convex; 2.5–3 mm long; 1.1–1.2 mm wide; falling entire.

GLUMES Glumes one the lower absent or obscure; shorter than spikelet; thinner than fertile lemma. Upper glume elliptic; 0.75 length of spikelet; membranous; without keels; 3 -veined. Upper glume primary vein conspicuous. Upper glume surface pubescent. Upper glume margins tuberculate; ciliate. Upper glume apex acute.

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; prominently veined; glabrous. Fertile lemma elliptic; 2.5–3 mm long; indurate; without keel; 7 -veined. Lemma surface papillose. Lemma margins involute. Palea involute; indurate.

FLOWER Lodicules 2; 0.3 mm long. Anthers 3; 1.6–2.2 mm long; purple.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 2 mm long. Embryo 0.33 length of caryopsis. Hilum elliptic.

DISTRIBUTION South America: western South America and southern South America.

NOTES Paniceae. Zuloaga et al 2001.

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