Ischaemum triticeum

HABIT Perennial. Culms rambling; 100–200 cm long; rooting from lower nodes. Culm-internodes 3–10 cm long. Culm-nodes glabrous. Lateral branches ample. Leaf-sheaths loose; longer than adjacent culm internode; hirsute; with tubercle-based hairs. Ligule an eciliate membrane; 1 mm long. Leaf-blade base cordate. Leaf-blades linear, or lanceolate; 8–15 cm long; 6–12 mm wide. Leaf-blade midrib prominent beneath. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2–3; paired, or digitate; appressed back to back; 5–10 cm long. Rhachis fragile at the nodes; angular; ciliate on margins. Rhachis internodes oblong; 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; 0.8–1 length of internode; ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; oblong; laterally compressed; 6–10 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; keeled; winged on keels. Companion sterile spikelet lemmas 2; enclosed by glumes; 1-awned.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 6–10 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus base truncate; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma; shiny. Lower glume oblong; 1 length of spikelet; coriaceous; 2-keeled; keeled all along; keeled laterally; winged on keel; winged broadly; winged above. Lower glume surface flat. Lower glume margins ciliolate. Lower glume apex obtuse. Upper glume lanceolate; coriaceous; 1-keeled; winged on keel; 7–9 -veined. Upper glume primary vein ciliolate. Upper glume apex acute.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret lanceolate; membranous; 7 -veined; ciliolate on margins. Fertile lemma oblong; membranous; without keel; 5 -veined. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; straight, or geniculate; 8–12 mm long overall; with twisted column. Column of lemma awn glabrous.

FLOWER Anthers 3; 4 mm long.

DISTRIBUTION Asia-tropical: Papuasia. Australasia: Australia.

NOTES Andropogoneae. Fl NSW 1993.

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