Ctenium floridanum

HABIT Perennial; culms solitary, or caespitose. Rhizomes elongated; scaly. Culms 50–110 cm long. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 1–3 mm long. Leaf-blades flat, or involute; 8–15 cm long; 2–3 mm wide.

INFLORESCENCE Inflorescence composed of racemes. Peduncle pubescent above.

Racemes 1; single; arcuate; unilateral; 5–20 cm long. Rhachis semiterete; 1 mm wide; smooth on surface, or scabrous on surface; glabrous on surface; 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; 6–7 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

GLUMES Glumes persistent; dissimilar; exceeding apex of florets; firmer than fertile lemma; gaping. Lower glume ovate; 2 mm long; 0.33 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface pubescent. Lower glume apex acute. Upper glume lanceolate; 6–7 mm long; 1.4 length of adjacent fertile lemma; herbaceous; with hyaline margins; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume surface scabrous; rough on veins. Upper glume apex acute, or 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; 4 mm long; membranous; 1-keeled; 3 -veined; ciliate on margins; fringed all along; acute; awned. Awn of lower sterile floret subapical; 2–4 mm long. Lemma of upper sterile floret lanceolate; 5–6 mm long; membranous; ciliate on margins; fringed in the middle; acute; awned. Awn of upper sterile floret subapical; straight; 4–5 mm long. Fertile lemma ovate; 4.5–5 mm long; membranous; keeled; 3 -veined. Lemma surface scabrous. Lemma margins ciliate; hairy above. Lemma apex awned; 1 -awned. Principal lemma awn subapical; 2–3 mm long overall. Palea 2 -veined. Apical sterile florets 1 in number; elliptic; 3 mm long. Apical sterile lemmas mucronate.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: southeast USA.

NOTES Cynodonteae. N Amer Fl 1993.

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