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 fastigiatus

HABIT Annual; caespitose. Culms 15–200 cm long. Ligule an eciliate membrane. Leaf-blades 5–30 cm long; 1–4 mm wide.

INFLORESCENCE Synflorescence compound. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole. Spatheole linear; 4–6 cm long.

Racemes 1; single; 2–5 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes clavate. 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 clavate; ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas; elliptic, or oblong; dorsally compressed; 5–9 mm long; longer than fertile. Companion sterile spikelet glumes membranous; glabrous; acute; awned; one glume awned; with 4–8 mm long awn. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear; laterally compressed; 4–5 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 linear; 1 length of spikelet; coriaceous; 2-keeled; keeled dorsally. Lower glume surface deeply depressed; glabrous. Upper glume linear; chartaceous; 1-keeled. Upper glume awned; 1 -awned. Upper glume awn 10–20 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 dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 25–40 mm long overall; with twisted column. Column of lemma awn glabrous. Palea lanceolate; 0 -veined; without keels.

DISTRIBUTION Africa: Macaronesia, west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, south, and western Indian ocean. Asia-temperate: Arabia. Asia-tropical: India, Indo-China, and Malesia. North America: Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, and Brazil.

NOTES Andropogoneae. FTEA.

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