Ischaemum nairii

HABIT Perennial; caespitose. Culms erect; 100–200 cm long. Culm-nodes bearded. Lateral branches ample. Leaf-sheaths 10–80 cm long; mostly shorter than adjacent culm internode; keeled; striately veined; pilose; with tubercle-based hairs. Ligule an eciliate membrane; 2–6 mm long. Leaf-blades lanceolate; 10–60 cm long; 10–20 mm wide. Leaf-blade surface pilose; with tubercle-based hairs. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2; paired; 5–12 cm long. Rhachis fragile at the nodes; angular; ciliate on margins. Rhachis internodes clavate; 2.5–3 mm long. 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; 1–1.5 mm long; ciliate; with 0.5–2 mm long hairs.

STERILE SPIKELETS Companion sterile spikelets well-developed; bisexual; ovate; laterally compressed; 5–5.5 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; keeled; winged on keels (1 keel); 7–9 -veined; smooth, or rugose. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 5.5–6 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus bearded; base truncate; inserted. Spikelet callus hairs 0.5–2 mm long.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume ovate; 1 length of spikelet; indurate; much thinner above; 2-keeled; keeled all along; keeled laterally; 9–11 -veined. Lower glume lateral veins obscure. Lower glume surface flat; rugose. Lower glume apex acute. Upper glume ovate; coriaceous; 1-keeled; winged on keel; winged near apex; 7–9 -veined. Upper glume lateral veins obscure. Upper glume margins ciliate.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret oblong; 4.5–5 mm long; membranous; 3 -veined; ciliate on margins; fringed above. Palea of lower sterile floret 4.5–5.4 mm long; pilose; adorned on flanks. Fertile lemma oblong; 3.5–4 mm long; membranous; without keel; 3 -veined. Lemma lateral veins obscure. Lemma margins ciliolate; hairy above. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 14–16 mm long overall; with twisted column. Column of lemma awn 6–7 mm long; glabrous. Palea 3–3.5 mm long.

FLOWER Lodicules 2; 0.5 mm long. Anthers 3; 2 mm long.

DISTRIBUTION Asia-tropical: India.

NOTES Andropogoneae. Fl Kerala 2006.

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