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 hamiltonii

HABIT Perennial. Culms robust. Culm-internodes distally glabrous. Leaf-sheaths without keel. Ligule a fringe of hairs. Leaf-blades 30–45 cm long; 5–10 mm wide. Leaf-blade surface smooth, or scaberulous; glabrous. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme. Peduncle pubescent above.

Panicle contracted; lanceolate; 15–25 cm long; 6–8 cm wide. Primary panicle branches appressed; 1–3 -nate; whorled at most nodes. Panicle axis smooth. 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; 0.5 length of fertile spikelet; villous; hairy all along but hairs longer above; with dark brown hairs.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; 10–20 mm long; longer than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; awned; one glume awned; with 10–12 mm long awn. Companion sterile spikelet lemmas enclosed by glumes; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; laterally compressed; 6–7 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 1 mm long; bearded; base pungent. Spikelet callus hairs dark brown.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; cartilaginous; without keels; 4 -veined. Lower glume surface scabrous; rough at apex. Lower glume apex mucronate. Upper glume oblong; 1-keeled; 3 -veined. Upper glume margins ciliate. Upper glume awned; 1 -awned. Upper glume awn 12 mm long.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline. Fertile lemma linear; hyaline; without keel; 1 -veined. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 45–60 mm long overall; with twisted column. Column of lemma awn pubescent. Palea absent or minute.

DISTRIBUTION Asia-tropical: India.

NOTES Andropogoneae. Haines 1999.

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