GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Ctenium brachystachyum

HABIT Perennial; caespitose. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Culms 35–60 cm long. Ligule an eciliate membrane. Leaf-blades filiform; involute; 15–25 cm long; 1–2 mm wide; stiff. Leaf-blade surface scabrous; rough on both sides.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; arcuate; unilateral; 2.5–4 cm long. Rhachis semiterete; glabrous on surface; scabrous 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; 4–5 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 ovate; 1.5 mm long; 0.33 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein tuberculate. Lower glume lateral veins absent. Lower glume apex acute. Upper glume elliptic; 4–5 mm long; 1.3 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 acute; awned; 1 -awned. Upper glume awn dorsal and oblique; 1–2 mm long.

FLORETS Basal sterile florets dissimilar; barren; without significant palea; attached to and deciduous with the fertile. Lemma of lower sterile floret lanceolate; 3–3.5 mm long; membranous; 1-keeled; 3 -veined; pilose; ciliate on margins; fringed below; acute; awned. Awn of lower sterile floret subapical; 1.5 mm long. Lemma of upper sterile floret oblong; 3.5 mm long; membranous; pilose; ciliate on margins; fringed in the middle; dentate; 2 -fid; awned. Awn of upper sterile floret terminal; straight; 2 mm long. Fertile lemma ovate; 4–5 mm long; membranous; keeled; 3 -veined. Lemma margins ciliate; hairy in the middle. Lemma apex emarginate; mucronate. Palea 2 -veined. Apical sterile florets 1 in number; oblong; 4 mm long.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: Brazil.

NOTES Cynodonteae. N Amer Fl 1993.

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