Ischaemum merrillii

HABIT Perennial. Culms erect; 30–50 cm long. Culm-internodes distally glabrous. Lateral branches lacking, or sparse. Leaf-sheaths mostly shorter than adjacent culm internode; keeled; outer margin hairy. Leaf-sheath oral hairs ciliate. Ligule an eciliate membrane; 2.5–4 mm long; pilose on abaxial surface; obtuse. Leaf-blade base with a false petiole; petiole 0.5–1.5 cm long. Leaf-blades linear, or lanceolate; 5–8 cm long; 6–8 mm wide; stiff. Leaf-blade surface pilose; sparsely hairy; hairy on both sides; with tubercle-based hairs. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2; paired; appressed back to back; 5 cm long. Rhachis fragile at the nodes; angular; ciliate on margins. Rhachis internodes oblong; 0.5 length of fertile spikelet; 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 oblong; 4 mm long; ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; laterally compressed; 6 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; keeled; winged on keels; 7 -veined; scaberulous; muticous. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong, or obovate; dorsally compressed; 7 mm long; 2 mm wide; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 1.5 mm long; pubescent; base truncate; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; coriaceous; much thinner above; purple; 2-keeled; keeled all along; keeled laterally; wingless; 6 -veined. Lower glume lateral veins without connecting veins; all extending to apex. Lower glume surface flat; asperulous; rough above. Lower glume apex dentate; 2 -fid. Upper glume ovate; 1 length of spikelet; chartaceous; 1-keeled; 5 -veined. Upper glume surface scabrous; rough above. Upper glume apex obtuse; muticous.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret lanceolate; hyaline; 3 -veined; acute. Fertile lemma lanceolate; hyaline; without keel; 3 -veined. Lemma apex lobed; 2 -fid; incised 0.33 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 12 mm long overall; with twisted column. Column of lemma awn 4 mm long; glabrous. Palea 1 length of lemma.

FLOWER Anthers 3.

DISTRIBUTION Asia-tropical: Malesia.

NOTES Andropogoneae. Hackel 1997.

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