Ischaemum celebicum

HABIT Perennial. Culms erect; robust; 100–200 cm long; 4–8 mm diam.; woody. Culm-internodes channelled; smooth; distally glabrous. Culm-nodes glabrous. Lateral branches ample; arising from upper culm. Leaf-sheaths mostly shorter than adjacent culm internode; glabrous on surface. Ligule a ciliolate membrane; 1.5–2 mm long. Leaf-blades 10–20 cm long; 5–10 mm wide. Leaf-blade surface glabrous, or pilose; sparsely hairy; hairy adaxially.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2; paired; 3–4 cm long. Rhachis fragile at the nodes; angular; ciliate on margins. Rhachis internodes clavate; flat and forming a U or V shape with the pedicel in rear view. Rhachis internode tip transverse; cupuliform.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels columnar; angular; ciliate; hairy on surface.

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas, or male; lanceolate; 5 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; winged on margins (one margin); muticous. Companion sterile spikelet lemmas 2; enclosed by glumes; 1-awned; with 4–6 mm long awn.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 6 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus square; pubescent; base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma; shiny. Lower glume lanceolate; 1 length of spikelet; coriaceous; much thinner above; 2-keeled; keeled above; keeled laterally; winged on keel; winged narrowly; winged near apex; 7–9 -veined. Lower glume surface convex; glabrous. Lower glume apex dentate; 2 -fid. Upper glume lanceolate; coriaceous; much thinner above; 1-keeled; keeled above; wingless; 3 -veined. Upper glume apex acuminate.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret lanceolate; 1 length of spikelet; membranous. Fertile lemma oblong; hyaline; without keel. Lemma apex lobed; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 10 mm long overall; with twisted column. Column of lemma awn glabrous.

FLOWER Anthers 3.

DISTRIBUTION Asia-tropical: Malesia.

NOTES Andropogoneae. Jansen 2001.

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