GrassBase - The Online World Grass Flora

Descriptions

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

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

Ischaemum sayajiraoi

HABIT Annual; caespitose; clumped loosely. Culms decumbent; 50–150 cm long; rooting from lower nodes. Culm-internodes elliptical in section; 10–20 cm long; ridged. Culm-nodes glabrous. Leaf-sheaths loose; 10–20 cm long; pilose. Leaf-sheath auricles erect. Ligule an eciliate membrane; 5–10 mm long. Leaf-blade base with a false petiole; petiole 0.2 cm long. Leaf-blades linear, or lanceolate; 25–50 cm long; 15–20 mm wide. Leaf-blade midrib conspicuous. Leaf-blade surface glabrous. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary.

Racemes 2; paired; appressed back to back; 10–15 cm long. Rhachis fragile at the nodes; angular; ciliate on margins. Rhachis internodes cuneate; 1 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 cuneate; 0.33 length of fertile spikelet; ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate, or ovate; dorsally compressed; 6–6.5 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes cartilaginous; 6–6.2 mm long; winged on margins; 9–12 -veined; rugose; ciliolate on margins; muticous. Companion sterile spikelet lemmas 2; enclosed by glumes; entire; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 6–7 mm long; 3–3.2 mm wide; falling entire; deciduous with accessory branch structures. Spikelet callus 0.5–0.75 mm long; pubescent; base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 6.5–6.8 mm long; 1 length of spikelet; coriaceous; much thinner above; yellow; 2-keeled; keeled all along; keeled laterally; winged on keel; winged narrowly; winged above; 7–12 -veined. Lower glume surface concave; rugose; rough below. Upper glume lanceolate, or oblong; chartaceous; 1-keeled; winged on keel; winged above. Upper glume primary vein ciliolate. Upper glume apex dentate; 2 -fid.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret present; lanceolate, or ovate; 6–6.2 mm long; 1 length of spikelet; hyaline; 3 -veined; ciliolate on margins; acuminate. Palea of lower sterile floret 6–6.2 mm long; 1 length of lemma. Fertile lemma oblong; 4–4.2 mm long; 1.5–1.8 mm wide; membranous; without keel. Lemma apex lobed; 2 -fid; incised 0.66 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 15–20 mm long overall; with twisted column. Column of lemma awn glabrous. Palea lanceolate; 5–5.2 mm long; 1.25 length of lemma; hyaline. Palea apex obtuse.

FLOWER Anthers 3; 3 mm long. Stigmas 2; purple. Styles 1.5 mm long.

FRUIT Caryopsis with adherent pericarp; oblong; dorsally compressed; without sulcus; 2.5–3 mm long; glabrous. Embryo 0.5 length of caryopsis. Hilum punctiform.

DISTRIBUTION Asia-tropical: India.

NOTES Andropogoneae. Raole et al 2013.

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