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 purpusii

HABIT Perennial; caespitose; clumped densely. Butt sheaths persistent and investing base of culm; with compacted dead sheaths. Culms 50–80 cm long; 0.5–1 mm diam. Culm-nodes flush with internodes; purple; glabrous, or pubescent. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths mostly shorter than adjacent culm internode; keeled; glabrous on surface, or pilose; outer margin hairy. Ligule a ciliolate membrane; 0.3–0.5 mm long. Collar pilose. Leaf-blades 15–25 cm long; 2–4 mm wide. Leaf-blade surface pilose; with tubercle-based hairs. Leaf-blade apex abruptly acute.

INFLORESCENCE Inflorescence composed of racemes. Peduncle 12–17 cm long.

Racemes 3–6; digitate; unilateral; 4–8 cm long. Central inflorescence axis 1–3 cm long. Rhachis angular; 0.4–0.5 mm wide; glabrous on surface; scabrous on margins; glabrous on margins. Spikelet packing adaxial. Raceme-bases brief; pubescent.

Spikelets appressed; solitary. Fertile spikelets sessile. Pedicels reduced to a stump; pubescent.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong, or ovate; dorsally compressed; 1.8–2.2 mm long; with hairs extending 0.1–0.3 mm beyond apex; 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; 2 -veined. Upper glume primary vein absent. Upper glume margins pubescent.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; 2 -veined; without midvein; pubescent on margins. Fertile lemma ovate; 1.7–2.1 mm long; indurate; without keel. Lemma margins involute. Lemma apex scabrous. Palea involute; indurate.

FLOWER Anthers 3; 1.2 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.