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 humboldtianum

HABIT Perennial; caespitose. Rhizomes elongated; scaly. Culms erect, or geniculately ascending; 60–120 cm long; 1.5–2 mm diam. Culm-internodes hollow; distally glabrous. Culm-nodes glabrous, or pubescent. Leaf-sheaths glabrous on surface to hispid; with tubercle-based hairs; outer margin hairy. Ligule an eciliate membrane; 1.8–3.8 mm long; brown. Leaf-blade base cordate. Leaf-blades lanceolate; 7–14 cm long; 8–17 mm wide. Leaf-blade surface glabrous to pubescent. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1–5; borne along a central axis; unilateral; 4–7.5 cm long. Central inflorescence axis 2–7 cm long. Rhachis narrowly winged; 1–1.5 mm wide; terminating in a sterile spikelet, or barren extension. Spikelet packing 2–4 -rowed.

Spikelets in pairs. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; acute; 3–3.7 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; without keels; 3 -veined. Upper glume surface glabrous, or puberulous. Upper glume margins tuberculate; ciliate. Upper glume hairs 2–3 mm long. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; ovate; 3–3.5 mm long; 1 length of spikelet; membranous; 3 -veined; smooth, or scaberulous; rough at apex; acute. Fertile lemma elliptic, or obovate; 2.3–2.7 mm long; indurate; pallid; shiny; without keel. Lemma surface smooth. Lemma margins involute. Palea involute; indurate.

FLOWER Anthers 3; 1.5–2.2 mm long; purple.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: Mexico. South America: Mesoamericana, northern South America, western South America, Brazil, and southern South America.

NOTES Paniceae. Fl Costaric 1993.

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