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.

Andropogon lacunosus

HABIT Perennial. Culms rambling; 30–60 cm long; wiry. Ligule an eciliate membrane. Leaf-blades 8–15 cm long; 2–5 mm wide.

INFLORESCENCE Inflorescence composed of racemes; terminal.

Racemes 2–3; paired, or digitate; 3–6 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes linear. Rhachis internode tip transverse; crateriform; with simple rim.

Spikelets appressed; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; dorsally compressed; 7–8 mm long; longer than fertile; persistent. Companion sterile spikelet glumes chartaceous; 3 -veined (raised); lacunose; glabrous; acuminate; muticous. Companion sterile spikelet lemmas enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 5–7 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus square, or oblong; 0.7 mm long; pilose; base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; coriaceous; 2-keeled; keeled laterally; winged on keel; winged narrowly. Lower glume intercarinal veins distinct. Lower glume surface convex and with a longitudinal median groove; lacunose (2 or more pits). Lower glume apex acuminate. Upper glume lanceolate; chartaceous; 1-keeled; keeled above. Upper glume awned; 1 -awned. Upper glume awn 1–2 mm long.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline; 2 -veined. Fertile lemma oblong; hyaline; without keel. Lemma apex lobed; 2 -fid; incised 0.25 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 8–14 mm long overall; with twisted column. Column of lemma awn glabrous. Palea hyaline; 0 -veined; without keels.

DISTRIBUTION Africa: west-central tropical, east tropical, southern tropical, and south.

NOTES Andropogoneae. FTEA.

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