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 polyptychos

HABIT Perennial; caespitose; clumped densely. Basal innovations flabellate. Culms 30–60 cm long. Ligule an eciliate membrane; 1–2 mm long. Leaf-blades erect; 15–25 cm long; 2–7 mm wide. Leaf-blade surface pilose.

INFLORESCENCE Inflorescence composed of racemes; terminal.

Racemes (1–)2–3(–6); paired, or digitate; 4–8 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes linear. Rhachis internode tip transverse; crateriform; with simple rim. Raceme-bases linear; subequal; 5–15 mm long.

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, or elliptic; dorsally compressed; 6–7 mm long; as long as fertile. Companion sterile spikelet glumes chartaceous; acute; muticous. Companion sterile spikelet lemmas enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic, or oblong; dorsally compressed; 6–7 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume elliptic; 1 length of spikelet; coriaceous; 2-keeled; keeled laterally; wingless. Lower glume intercarinal veins distinct; 5 in number. Lower glume surface flat, or concave. Lower glume apex acute. Upper glume lanceolate; chartaceous; 1-keeled; wingless. Upper glume muticous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline; 2 -veined. Fertile lemma linear; hyaline; without keel. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 9–17 mm long overall; with twisted column. Column of lemma awn glabrous.

DISTRIBUTION Asia-tropical: India and Indo-China.

NOTES Andropogoneae. WDC.

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