Ctenium concissum

HABIT Perennial; caespitose. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Culms erect; 35–100 cm long. Leaf-sheaths scaberulous. Ligule an eciliate membrane; 1 mm long; truncate. Leaf-blades flat, or involute; 15–30 cm long; 2–4 mm wide. Leaf-blade surface scaberulous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes. Peduncle pubescent above.

Racemes 1; single; arcuate, or flexuous; unilateral; 5–16 cm long. Rhachis semiterete; 1.5 mm wide; scabrous on surface; glabrous on surface; pubescent on margins; terminating in a barren extension; extension subulate. Spikelet packing broadside to rhachis; crowded; regular; 2 -rowed.

Spikelets pectinate; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 2 basal sterile florets; 1 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 8–9 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pilose.

GLUMES Glumes persistent; dissimilar; exceeding apex of florets; firmer than fertile lemma; gaping. Lower glume lanceolate; 2 mm long; 0.25 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 8–9 mm long; 2 length of adjacent fertile lemma; herbaceous; with hyaline margins; 1-keeled; 3 -veined. Upper glume primary vein tuberculate. Upper glume surface tuberculate; rough on veins. Upper glume apex acuminate; awned; 1 -awned. Upper glume awn dorsal and oblique; 3–5 mm long.

FLORETS Basal sterile florets dissimilar; barren; without significant palea; attached to and deciduous with the fertile. Lemma of lower sterile floret elliptic; 3 mm long; membranous; 1-keeled; ciliate on margins; fringed all along; acute; awned. Awn of lower sterile floret subapical; 4 mm long. Lemma of upper sterile floret elliptic; 4.5–5 mm long; membranous; ciliate on margins; fringed above; acute; awned. Awn of upper sterile floret subapical; 10–15 mm long. Fertile lemma ovate; 4–5 mm long; membranous; keeled; 3 -veined. Lemma margins ciliate; hairy above. Lemma hairs 3 mm long. Lemma apex awned; 1 -awned. Principal lemma awn subapical; 3 mm long overall. Palea 2 -veined. Palea keels scaberulous. Palea apex obtuse; muticous, or with excurrent keel veins. Apical sterile florets 1 in number; elliptic; 3 mm long. Apical sterile lemmas awned; 1 -awned. Apical sterile lemma awns 1 mm long.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: Mesoamericana.

NOTES Cynodonteae. N Amer Fl 1993.

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