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.

Axonopus leptostachyus

HABIT Perennial. Culms robust; 50–150 cm long; 2–5 -noded. Culm-internodes terete, or elliptical in section. Culm-nodes swollen; glabrous, or pubescent. Lateral branches lacking. Leaves cauline; without demarcation between sheath and blade. Leaf-sheaths 10–30 cm long; longer than adjacent culm internode; keeled; glabrous on surface. Ligule a ciliolate membrane; 0.3 mm long. Leaf-blades conduplicate; 1–50 cm long; 3–5 mm wide; stiff. Leaf-blade apex abruptly acute.

INFLORESCENCE Inflorescence composed of racemes; with 1–2 peduncles per sheath. Peduncle 30–75 cm long.

Racemes 5–15; digitate; spreading; unilateral; 5–25 cm long. Central inflorescence axis 3–15 cm long. Rhachis angular; 0.3–0.5 mm wide; drab; glabrous on surface; scabrous on margins; glabrous on margins. Spikelet packing adaxial; 5.5–11 spikelets per cm. Raceme-bases brief; pubescent.

Spikelets appressed; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; acute; 2.3–2.5 mm long; 0.7–0.8 mm wide; falling entire.

GLUMES Glumes one the lower absent or obscure; reaching apex of florets; thinner than fertile lemma. Upper glume 1 length of spikelet; membranous; 5–7 -veined. Upper glume primary vein absent, or obscure. Upper glume surface glabrous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; 1.2–1.4 length of fertile lemma; 1 length of spikelet; 5–7 -veined; without midvein, or with evident midvein; glabrous. Fertile lemma 1.6–2 mm long; indurate; light brown; shiny; without keel. Lemma margins involute. Lemma apex without ornament, or pubescent. Palea involute; indurate.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Paniceae. Black 1994.

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