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.

Polytoca wallichiana

HABIT Annual. Culms 30–120 cm long; with prop roots. Leaf-sheaths hispid; with tubercle-based hairs. Ligule a ciliolate membrane. Leaf-blades linear, or lanceolate; 20–90 cm long; 25–35 mm wide.

INFLORESCENCE Monoecious; with male terminal and mixed axillary inflorescences. Synflorescence compound; fasciculate; 6–10 cm long; dense. Inflorescence composed of racemes; axillary; subtended by a spatheole; embraced at base by subtending leaf. Spatheole lanceolate; herbaceous.

Racemes 1–9 (1 of them female); single, or digitate; 3–8 cm long; bearing few fertile spikelets; bearing 3–7 fertile spikelets on each (and 0–10 male spikelets). Rhachis fragile at the nodes; flattened; pubescent on surface; ciliate on margins. Rhachis internodes clavate; 5–6 mm long; bearing a sterile companion laterally. Rhachis internode tip crateriform.

Sexes segregated; on unisexual branches, or bisexual branches; with male above, or below. Spikelets embracing internode; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Male spikelets sessile and pedicelled; 2 in a cluster. Pedicels fused to internode; united wholly.

STERILE SPIKELETS Companion sterile spikelets represented by single glumes; lanceolate; 10–20 mm long; longer than fertile; separately deciduous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 6–7 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus base truncate; with central peg; attached transversely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; indurate; much thinner above; pallid; 2-keeled; keeled above; winged on keel; winged broadly; winged above. Lower glume surface convex; laterally waisted; pubescent; hairy below. Lower glume apex entire, or erose; emarginate, or obtuse. Upper glume oblong; 0.75 length of spikelet; coriaceous; without keels; 7 -veined. Upper glume apex caudate.

FLORETS Fertile florets female. Fertile lemma oblong; 4 mm long; cartilaginous; without keel; 9 -veined. Lemma apex cuspidate. Palea oblong; 0.75 length of lemma; hyaline; 1 -veined; without keels. Palea apex cuspidate.

FRUIT Caryopsis with adherent pericarp; square; flattened; concavo-convex; 2.5 mm long. Hilum punctiform.

MALE Male inflorescence of subdigitate racemes. Male spikelets distinct from female; with free pedicels; 2 flowered; ovate; 6 mm long. Male spikelet glumes 2; awned (5–15mm). Male spikelet lemma 3 -veined.

DISTRIBUTION Asia-tropical: India and Indo-China.

NOTES Andropogoneae. Bor.

ADDITIONAL CHARACTERS Male racemes flexuous.

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