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.

Cymbopogon pruinosus

HABIT Perennial; caespitose. Butt sheaths persistent and investing base of culm; with compacted dead sheaths. Culms erect, or geniculately ascending; 20–60 cm long. Culm-internodes distally glabrous. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 2 mm long; membranous. Leaf-blade base broadly rounded, or cordate, or amplexicaul. Leaf-blades 40–80 cm long; 5–15 mm wide; aromatic. Leaf-blade surface glabrous.

INFLORESCENCE Synflorescence compound; linear, or paniculate; 7–20 cm long; dense. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole elliptic; 1.7–2.6 cm long.

Racemes 2; paired; deflexed; 1.5–1.7 cm long. Rhachis fragile at the nodes; semiterete; glabrous on surface; ciliate on margins. Rhachis internodes linear. Rhachis internode tip transverse; cupuliform. Raceme-bases flattened; unequal (the longer measured).

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; semiterete; ciliate.

STERILE SPIKELETS Basal sterile spikelets well-developed; 2 in number (lower raceme); 0 in upper raceme; with normal internodes; sessile and pedicelled. Basal sterile spikelet pedicels free; linear. Basal sterile spikelets equalling fertile.

Companion sterile spikelets well-developed; male; lanceolate; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes chartaceous; 7 -veined; acute; muticous. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 4 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume elliptic; 1 length of spikelet; chartaceous; 2-keeled; keeled all along; keeled laterally; winged on keel; winged broadly. Lower glume intercarinal veins distinct; 2 in number. Lower glume surface with V-shaped depression. Lower glume apex dentate; 3 -fid. Upper glume lanceolate; 1-keeled. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret hyaline. Fertile lemma lanceolate; hyaline; without keel. Lemma apex lobed; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 11 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Africa: western Indian ocean.

NOTES Andropogoneae. Soenarko 1993.

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