Coelorachis rugosa

HABIT Perennial. Basal innovations flabellate. Culms 75–130 cm long. Lateral branches ample. Leaf-sheaths keeled. Ligule an eciliate membrane; truncate. Leaf-blades conduplicate; 20–40 cm long; 2–8 mm wide. Leaf-blade surface glabrous.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary. Peduncle widened at apex.

Racemes 1; single; smoothly terete; 4–8 cm long; 2–2.5 mm wide. Rhachis fragile at the nodes; semiterete; glabrous on surface. Rhachis internodes clavate; 2.5–3 mm long. Rhachis internode tip transverse; crateriform; with simple rim.

Spikelets sunken; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels columnar; semiterete; 2.5–3 mm long; glabrous.

STERILE SPIKELETS Companion sterile spikelets rudimentary; comprising 2 unequal glumes without lemmas; ovate; 0.5–1 mm long; shorter than fertile; deciduous with the fertile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; 3.5–5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus base truncate; with central peg; attached transversely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume ovate; 1 length of spikelet; coriaceous; 2-keeled; winged on keel; winged narrowly; winged above. Lower glume surface rugose. Upper glume oblong; membranous; 1-keeled.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret oblong; hyaline. Fertile lemma elliptic; hyaline; without keel.

DISTRIBUTION North America: northeast USA, south-central USA, and southeast USA.

NOTES Andropogoneae. Gr Texas 1994.

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