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Descriptions

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

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

Ischaemum pappinisseriense

HABIT Annual; caespitose. Culms erect, or geniculately ascending; 30–60 cm long; rooting from lower nodes. Culm-internodes smooth. Culm-nodes pubescent. Leaf-sheaths 4–7 cm long; keeled; striately veined; glabrous on surface. Ligule an eciliate membrane; 3–5 mm long. Leaf-blade base cuneate; without a false petiole, or with a brief petiole-like connection to sheath. Leaf-blades linear, or lanceolate; 4–8 cm long; 3–6 mm wide.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2; paired; appressed back to back; 4–5 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes inflated; 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 clavate; 1 mm long; ciliate; hairy on one margin.

STERILE SPIKELETS Companion sterile spikelets well-developed; comprising 2 subequal glumes without lemmas; oblong; 2.5–3 mm long; shorter than fertile. Companion sterile spikelet glumes chartaceous; keeled; winged on keels; 9–11 -veined; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic, or oblong; dorsally compressed; 5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus oblong; 0.5–0.75 mm long; bearded; base obtuse; inserted. Spikelet callus hairs 1–1.5 mm long.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume elliptic, or oblong; 1 length of spikelet; coriaceous; much thinner above; 2-keeled; keeled all along; keeled laterally; winged on keel; winged broadly; winged above; 13–15 -veined. Lower glume surface muricate; rough on flanks. Lower glume apex emarginate. Upper glume lanceolate; chartaceous; 1-keeled; 5 -veined.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret lanceolate, or elliptic; 4–4.5 mm long; membranous; 3 -veined; ciliolate on margins; acute. Palea of lower sterile floret 3.5–4 mm long. Fertile lemma oblong; 3–4 mm long; membranous; without keel. Lemma apex lobed; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 22.5 mm long overall; with twisted column. Column of lemma awn 7.5 mm long; glabrous. Palea 2.5–3 mm long.

FLOWER Lodicules 2; 0.5 mm long. Anthers 3; 1.2 mm long.

FRUIT Caryopsis with adherent pericarp; oblong; 2 mm long.

DISTRIBUTION Asia-tropical: India.

NOTES Andropogoneae. Ravi et al 2006.

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