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.

Chrysopogon castaneus

HABIT Perennial. Culms geniculately ascending; 40–100 cm long. Ligule a ciliate membrane; 0.5 mm long. Leaf-blades 8–25 cm long; 3–8 mm wide. Leaf-blade surface glabrous. Leaf-blade margins tuberculate-ciliate.

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme.

Panicle open; ovate; 8–25 cm long; 3–8 cm wide; bearing few spikelets. Primary panicle branches 2 -nate; 2–5 cm long. Panicle branches capillary.

Racemes bearing a triad of spikelets; 1 fertile spikelets on each. Rhachis obsolete.

Spikelets in threes. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 2 in the cluster. Pedicels linear; 5–6 mm long; 0.5 length of fertile spikelet.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; 10.5–12 mm long; longer than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous. Companion sterile spikelet lemmas 1; enclosed by glumes; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 8 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 2 mm long; bearded; base pungent. Spikelet callus hairs red; 2–3 mm long.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 8 mm long; 1 length of spikelet; cartilaginous; without keels. Lower glume surface tuberculate; rough above. Lower glume apex dentate; 2 -fid. Upper glume lanceolate; 1-keeled. Upper glume primary vein tuberculate (minutely). Upper glume awned; 1 -awned. Upper glume awn 1.5–4 mm long.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; hyaline. Fertile lemma oblong; hyaline; without keel. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 60–70 mm long overall; with twisted column. Column of lemma awn puberulous; with 0.3 mm long hairs. Palea absent or minute.

FLOWER Anthers 3; 2.2–3.5 mm long.

DISTRIBUTION Asia-tropical: India.

NOTES Andropogoneae. Veldkamp & Sal 2002.

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