Andropogon perdignus

HABIT Perennial; caespitose. Culms erect; 200–300 cm long. Culm-internodes glaucous. Culm-nodes glabrous. Leaf-sheaths mostly shorter than adjacent culm internode; glabrous on surface. Ligule an eciliate membrane; 2 mm long. Leaf-blades 20–45 cm long; 10–15 mm wide. Leaf-blade midrib prominent beneath. Leaf-blade surface glabrous.

INFLORESCENCE Synflorescence compound; linear; 25–35 cm long; open. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; embraced at base by subtending leaf. Spatheole lanceolate; 2–4 cm long.

Racemes 1; single; 2–4 cm long. Rhachis fragile at the nodes; scabrous on surface; villous on margins. Rhachis internodes clavate; 3 mm long. Rhachis internode tip transverse; cupuliform; with simple rim.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; villous; hairy on margins.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; 2.5–3 mm long; longer than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous. 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; 4–5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus 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; 4 -veined. Lower glume primary vein scaberulous; ciliolate. Lower glume surface concave. Upper glume linear; coriaceous; 1-keeled; 3 -veined. Upper glume primary vein pubescent (above). Upper glume muticous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline; 2-keeled; ciliolate on margins. Fertile lemma lanceolate; 3–3.7 mm long; hyaline; without keel. Lemma apex lobed; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 15–20 mm long overall; with a straight or slightly twisted column. Column of lemma awn glabrous. Palea 2.5–3 mm long; hyaline; 2 -veined; 2-keeled.

FLOWER Lodicules 2; 0.5–0.7 mm long. Anthers 3; 1.5 mm long.

DISTRIBUTION South America: northern South America.

NOTES Andropogoneae. Sohns 2004.

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