GrassBase - The Online World Grass Flora

Descriptions

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

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

Ctenium aromaticum

HABIT Perennial; caespitose. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Culms erect; 100–150 cm long. Leaf-sheaths scaberulous. Ligule an eciliate membrane; 1–3 mm long; erose. Leaf-blades flat, or involute; 5–10 cm long; 1–3 mm wide; aromatic. Leaf-blade surface smooth, or scaberulous.

INFLORESCENCE Inflorescence composed of racemes. Peduncle pubescent above.

Racemes 1; single; arcuate; unilateral; 5–15 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; 5–7 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; 2.5 mm long; 0.3–0.5 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 5–7 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, 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; 3–5 mm long; membranous; 1-keeled; ciliate on margins; fringed in the middle; acute; awned. Awn of lower sterile floret dorsal; 2–3 mm long. Lemma of upper sterile floret elliptic; 4–6 mm long; membranous; tufted on margins; fringed in the middle; acute; awned. Awn of upper sterile floret dorsal; curved; 4–5 mm long. Fertile lemma ovate; 4.5–5.5 mm long; membranous; keeled; 3 -veined. Lemma margins ciliate; hairy in the middle. Lemma apex awned; 1 -awned. Principal lemma awn subapical; 1–2 mm long overall. Palea 2 -veined. Apical sterile florets 1 in number; elliptic; 3–4 mm long.

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.