GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Ischaemum santapaui

HABIT Annual; caespitose. Culms geniculately ascending; 100–200 cm long; 1–2 mm diam.; with prop roots. Culm-internodes distally glabrous. Lateral branches ample. Ligule an eciliate membrane; 2–3 mm long. Leaf-blade base broadly rounded, or cordate. Leaf-blades 5–10 mm wide. Leaf-blade surface scabrous; rough on both sides; glabrous. Leaf-blade apex acute.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary.

Racemes 2; paired; appressed back to back; 5–6 cm long. Rhachis fragile at the nodes; angular; ciliate on margins. Rhachis internodes linear; 2.8–4 mm long; 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 linear; 1–1.5 mm long; 0.25 length of fertile spikelet; ciliate; with grey hairs.

STERILE SPIKELETS Companion sterile spikelets represented by single glumes, or rudimentary; comprising 2 subequal glumes without lemmas; lanceolate; 1–2 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; keeled; winged on keels; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 4.5 mm long; 1.75 mm wide; falling entire; deciduous with accessory branch structures. Spikelet callus oblong; 0.5 mm long; base truncate; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; membranous, or coriaceous; much thinner above; 2-keeled; keeled all along; keeled laterally; 10–11 -veined. Lower glume surface convex; rugose; rough generally, or on flanks. Lower glume apex obtuse. Upper glume lanceolate; chartaceous, or coriaceous; 1-keeled; keeled above. Upper glume surface scabrous. Upper glume apex acute; mucronate.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret lanceolate; 3.75–4.25 mm long; membranous; acute. Palea of lower sterile floret 0.75 length of lemma. Fertile lemma oblong; 3.5 mm long; membranous; without keel. Lemma apex lobed; 2 -fid; incised 0.5 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 15 mm long overall; with twisted column. Column of lemma awn 6 mm long; glabrous. Palea 2 mm long.

FLOWER Anthers 3; 1.5–2.5 mm long.

DISTRIBUTION Asia-tropical: India.

NOTES Andropogoneae. Bor 1994.

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