Ctenium chapadense

HABIT Perennial; caespitose. Butt sheaths persistent and investing base of culm; with compacted dead sheaths, or fibrous dead sheaths. Culms erect; 70–145 cm long. Leaves heterophyllous (culm leaves filiform). Ligule an eciliate membrane. Leaf-blades flat, or involute; 20–34 cm long; 4–7 mm wide. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1–3; single, or digitate; straight, or flexuous; unilateral; 7–18 cm long. Rhachis semiterete; 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; 6–8 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; 3–4 mm long; 0.5 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume elliptic; 6–8 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; 3–4 mm long.

FLORETS Basal sterile florets dissimilar; barren; without significant palea; attached to and deciduous with the fertile. Lemma of lower sterile floret ovate; 2 mm long; membranous; 1-keeled; 3 -veined; ciliate on margins; fringed all along; acute; awned. Awn of lower sterile floret subapical; 5 mm long. Lemma of upper sterile floret elliptic; 3 mm long; membranous; tufted on margins; fringed above; acute; awned. Awn of upper sterile floret subapical; 4 mm long. Fertile lemma ovate; 3–3.5 mm long; membranous; keeled; 3 -veined. Lemma margins ciliate; hairy above. Lemma hairs 2 mm long. Lemma apex awned; 1 -awned. Principal lemma awn subapical; 5 mm long overall. Palea 2 -veined. Apical sterile florets 1 in number; linear; 2 mm long.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: Brazil.

NOTES Cynodonteae. Gr Bahia.

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