Chrysopogon borneensis

HABIT Perennial. Culms 25–50 cm long. Ligule a fringe of hairs; 0.3 mm long. Leaf-blades conduplicate; 4–10 cm long; 1.2–3.5 mm wide. Leaf-blade margins ciliate; hairy at base.

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme.

Panicle open; 3–4 cm long; 1.5 cm wide; bearing few spikelets. Primary panicle branches whorled at most nodes; simple; 3 cm long.

Racemes bearing a triad of spikelets; 1 fertile spikelets on each. Rhachis obsolete. Raceme-bases filiform; 25 mm long.

Spikelets in threes. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 2 in the cluster. Pedicels linear; 2.25–3.5 mm long; 0.5 length of fertile spikelet; ciliate; with 1.8–1.9 mm long hairs.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; dorsally compressed; 4.65–5.25 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; smooth; puberulous; mucronate, or awned; one glume awned; with 0.4–3 mm long awn. Companion sterile spikelet lemmas 1; enclosed by glumes; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; laterally compressed; 6.35–6.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus oblong; 0.9–1.35 mm long; pilose; base pungent; attached obliquely. Spikelet callus hairs yellow; 1.2–1.3 mm long.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 5–8 mm long; 1 length of spikelet; cartilaginous; without keels; 5–7 -veined. Lower glume surface convex; smooth; hispidulous. Lower glume apex acute. Upper glume lanceolate; 1-keeled; 3–5 -veined. Upper glume primary vein eciliate, or ciliolate. Upper glume mucronate, or awned; 1 -awned. Upper glume awn 1–4.5 mm long; glabrous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; hyaline; 2 -veined. Fertile lemma oblong; hyaline; without keel. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 11–20 mm long overall; clearly exserted from spikelet; with twisted column. Column of lemma awn puberulous; with 0.1 mm long hairs.

FLOWER Lodicules 2; glabrous. Anthers 3; 2–2.2 mm long (sessile), or 1.8–2 mm long (pedicelled).

DISTRIBUTION Asia-tropical: Malesia.

NOTES Andropogoneae. Veldkamp 1998.

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