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.

Brachiaria venosa

HABIT Annual. Culms erect, or geniculately ascending; 40 cm long. Culm-internodes 6 cm long; distally glabrous. Culm-nodes pubescent. Leaf-sheaths 3–7 cm long; glabrous on surface; outer margin hairy. Ligule a ciliolate membrane; 1 mm long. Collar glabrous. Leaf-blade base broadly rounded. Leaf-blades lanceolate; 4–9 cm long; 5–9 mm wide. Leaf-blade surface pubescent. Leaf-blade margins cartilaginous. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes borne along a central axis; unilateral; 5–10 cm long; secondarily branched. Central inflorescence axis 2–4 cm long. Rhachis wingless; angular; glabrous on surface; scaberulous on margins; terminating in a sterile spikelet. Spikelet packing irregular. Raceme-bases linear.

Spikelets solitary, or in pairs. Fertile spikelets pedicelled. Pedicels linear; scaberulous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; compressed slightly; 2.4–2.6 mm long; 1–1.4 mm wide; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 1.3–1.8 mm long; 0.5 length of spikelet; membranous; without keels; 5–7 -veined. Lower glume lateral veins transversely connected at apex. Lower glume apex acuminate. Upper glume oblong; 1 length of spikelet; membranous; without keels; 9–11 -veined. Upper glume lateral veins transversely connected at apex. Upper glume surface glabrous. Upper glume apex acute.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; membranous; 11 -veined; with veins transversely connected at apex; glabrous; acute. Palea of lower sterile floret 0.5 length of lemma. Fertile lemma elliptic; 1.9 mm long; 1 mm wide; indurate; without keel; 5 -veined. Lemma surface rugose. Lemma margins involute. Lemma apex apiculate. Palea involute; indurate; without keels. Palea surface rugose.

FLOWER Anthers 3; 0.8 mm long.

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

DISTRIBUTION North America: Mexico.

NOTES Paniceae. Morrone 1994.

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