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.

Lasiacis oaxacensis

HABIT Perennial. Culms prostrate; 50–200 cm long; 2–5 mm diam.; rooting from lower nodes. Culm-internodes solid; distally glabrous. Culm-nodes glabrous. Lateral branches ample. Leaf-sheaths glabrous on surface; outer margin hairy. Ligule a ciliolate membrane; (2–)2.5–5(–6) mm long; brown; pubescent on abaxial surface. Collar glabrous, or pubescent. Leaf-blades linear, or lanceolate; (13–)17–29 cm long; 12–24 mm wide. Leaf-blade surface scabrous; glabrous. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 16–31 cm long; with spikelets clustered towards branch tips. Primary panicle branches spreading; (4–)9–18(–24) cm long.

Spikelets in pairs. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets obovate; tilted on the pedicel; dorsally compressed; 3.8–4.2 mm long; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma; shiny. Lower glume oblate; 1.6–2.3 mm long; 0.5 length of spikelet; membranous; black; without keels; 4–6 -veined. Lower glume surface woolly; hairy at apex. Lower glume apex obtuse. Upper glume ovate; 1 length of spikelet; membranous; black; without keels; 7–11 -veined. Upper glume surface woolly; hairy at apex. Upper glume apex obtuse.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; membranous; 9–11 -veined; woolly; hairy at apex; obtuse. Palea of lower sterile floret 1 length of lemma. Fertile lemma ovate; dorsally compressed; 3.2–3.6 mm long; 1.9–2.3 mm wide; indurate; dark brown; shiny; without keel. Lemma margins involute. Lemma apex obtuse; with a shallow excavation and woolly. Palea indurate. Palea apex pubescent.

FLOWER Anthers 3; 1–2.3 mm long. Stigmas purple.

FRUIT Caryopsis with adherent pericarp; 2 mm long.

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

NOTES Paniceae. Davidse.

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