Andropogon carinatus

HABIT Perennial. Culms 50 cm long. Ligule an eciliate membrane. Leaf-blades 7–20 cm long; 2–3 mm wide. Leaf-blade apex abruptly acute.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2–3; paired, or digitate; 2–4 cm long. Rhachis fragile at the nodes; villous on margins. Rhachis hairs evenly distributed; 4 mm long. Rhachis internodes linear; 4 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; 4 mm long; villous; hairy all along; with 4 mm long hairs.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; 5 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; glabrous; acute; 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 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 lanceolate; 1 length of spikelet; coriaceous; 2-keeled; keeled dorsally. Lower glume surface concave, or deeply depressed. Upper glume linear; coriaceous; 1-keeled. Upper glume muticous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline. Fertile lemma lanceolate; hyaline; without keel. Lemma apex lobed; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 8–12 mm long overall; with twisted column. Column of lemma awn glabrous.

FLOWER Anthers 3.

DISTRIBUTION South America: Mesoamericana, northern South America, western South America, and Brazil.

NOTES Andropogoneae. WDC 1995.

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