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.

Cymbopogon obtectus

HABIT Perennial; caespitose. Butt sheaths pubescent; persistent and investing base of culm. Culms 50–100 cm long; 1–2 -noded. Culm-nodes glabrous, or pubescent. Ligule an eciliate membrane; 3–5 mm long. Leaf-blades flat, or conduplicate, or revolute; 15–35 cm long; 1.25–2.5 mm wide; aromatic. Leaf-blade margins scaberulous. Leaf-blade apex attenuate.

INFLORESCENCE Synflorescence compound; linear, or paniculate; 7–25 cm long; dense. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole 2–3.2 cm long; herbaceous. Peduncle 0.5–1 cm long.

Racemes 2; paired; deflexed; 1.5–2.5 cm long. Rhachis fragile at the nodes; semiterete; villous on surface; villous on margins. Rhachis hairs 4.5–7 mm long. Rhachis internodes linear; 2.75–3.5 mm long. Rhachis internode tip transverse; cupuliform. Raceme-bases flattened; subequal.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; semiterete; 2.75–3.5 mm long; villous; with 4.5–7 mm long hairs.

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

Companion sterile spikelets well-developed; comprising 2 unequal glumes without lemmas, or containing empty lemmas; lanceolate; 3.5–5 mm long; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes chartaceous; 11–13 -veined; glabrous; 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 lanceolate; dorsally compressed; acute; 5.2–6.4 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus bearded; base obtuse; inserted. Spikelet callus hairs 4–5 mm long.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; chartaceous; 2-keeled; keeled laterally; wingless. Lower glume intercarinal veins distinct; 2–5 in number. Lower glume surface concave. Lower glume apex acuminate. Upper glume lanceolate; 1-keeled; keeled above; 5–7 -veined. Upper glume margins ciliolate. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 3.7–4.5 mm long; hyaline; 2–3 -veined; ciliolate on margins; acute. Fertile lemma lanceolate; 3.6–4.5 mm long; hyaline; without keel; 1–3 -veined. Lemma apex lobed; 2 -fid; incised 0.15–0.33 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; straight, or geniculate; 6–8 mm long overall; without a column, or with a straight or slightly twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 3; 1.7–2 mm long.

FRUIT Caryopsis with adherent pericarp; orbicular.

DISTRIBUTION Australasia: Australia.

NOTES Andropogoneae. Vickery.

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