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.

Andropogon ibityensis

HABIT Perennial; caespitose; clumped densely. Basal innovations flabellate. Culms erect; 45–90 cm long. Lateral branches lacking, or sparse. Leaves mostly basal. Leaf-sheaths keeled. Leaf-sheath oral hairs scanty, or ciliate. Ligule a ciliolate membrane; 0.5–1.2 mm long; membranous; truncate. Leaf-blades curled; flat, or conduplicate; 15–25 cm long; 2–4 mm wide; red. Leaf-blade surface glabrous; hairless except near base. Leaf-blade margins scaberulous. Leaf-blade apex obtuse, or acute.

INFLORESCENCE Synflorescence simple. Inflorescence composed of racemes.

Racemes (4–)5–9; digitate; 4–7.5 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis hairs 1–3 mm long. Rhachis internodes filiform; 3 mm long. Rhachis internode tip transverse; cupuliform; 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; with 1–3 mm long hairs.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; dorsally compressed; 4–5.5(–6) mm long; as long as fertile. Companion sterile spikelet glumes chartaceous; glabrous; acuminate; muticous, or mucronate. Companion sterile spikelet lemmas enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 4.5–5.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus brief; pilose; base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 4.5–5.5 mm long; 1 length of spikelet; coriaceous; 2-keeled; keeled dorsally. Lower glume surface concave; glabrous. Lower glume apex acuminate. Upper glume lanceolate; chartaceous; 1-keeled. Upper glume muticous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline. Fertile lemma oblong; 3 mm long; hyaline; without keel. Lemma apex lobed; 2 -fid; incised 0.33–0.5 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 8–13 mm long overall; with twisted column. Column of lemma awn glabrous.

DISTRIBUTION Africa: western Indian ocean.

NOTES Andropogoneae. Vorontsova 2013.

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