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.

Lasiacis nigra

HABIT Perennial; caespitose. Culms scandent; 100–800 cm long; 5–10 mm diam.; woody. Culm-internodes hollow; distally with pubescent line. Culm-nodes glabrous. Leaf-sheaths glabrous on surface, or pilose; outer margin hairy. Leaf-sheath oral hairs ciliate; 3–4 mm long. Ligule an eciliate membrane, or a ciliolate membrane; 0.5–1.3(–2) mm long; white, or brown; glabrous on abaxial surface, or pubescent on abaxial surface. Collar glabrous, or pubescent, or pilose. Leaf-blade base asymmetrical. Leaf-blades linear, or lanceolate; 5–11(–15) cm long; (3–)6–18(–26) mm wide. Leaf-blade surface glabrous, or pilose. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; (2–)5–12(–19) cm long. Primary panicle branches ascending; 1–11 cm long. Panicle branches glabrous, or pubescent; glabrous in axils, or pubescent in axils, or bearded in axils.

Spikelets spreading; solitary. Fertile spikelets pedicelled. Pedicels flexuous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets obovate; tilted on the pedicel; dorsally compressed; (3.6–)4–5(–5.5) mm long; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma; shiny. Lower glume oblate; 2–2.7 mm long; 0.5 length of spikelet; membranous; black; without keels; 5–13 -veined. Lower glume surface woolly; hairy at apex. Lower glume apex obtuse. Upper glume ovate; 1 length of spikelet; membranous; black; without keels; 7–13 -veined. Upper glume surface woolly; hairy at apex. Upper glume apex obtuse.

FLORETS Basal sterile florets male, or barren; 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 0.5–1 length of lemma. Fertile lemma ovate; dorsally compressed; 3.8–4.6 mm long; 2.5–2.9 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; 2.1–2.8 mm long; pallid.

FRUIT Caryopsis with adherent pericarp; 2.4–2.7 mm long; light brown.

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

NOTES Paniceae. Davidse.

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