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.

Rottboellia paradoxa

HABIT Perennial. Culms erect; 170 cm long. Leaf-sheaths hispid; with tubercle-based hairs. Ligule a ciliolate membrane; 2.5 mm long. Leaf-blades 25–50 cm long; 8–16 mm wide. Leaf-blade surface pilose; sparsely hairy; hairy on both sides; with tubercle-based hairs. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary.

Racemes 1; single; smoothly terete; unilateral. Rhachis fragile at the nodes; subcylindrical and excavated; glabrous on margins; terminating in a sterile spikelet. Spikelet packing abaxial; regular. Rhachis internodes oblong. Rhachis internode tip transverse; crateriform; with simple rim.

Spikelets sunken; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels fused to internode; united below; oblong; flattened; 4–5.2 mm long; ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas; ovate; dorsally compressed; 5 mm long; deciduous with the fertile. Companion sterile spikelet glumes indurate; 10 -veined; glabrous; eciliate on margins, or ciliolate on margins; muticous. Companion sterile spikelet lemmas enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 7–7.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus base truncate; with central peg; attached transversely.

GLUMES Glumes dissimilar; with lower wider than upper; reaching apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; coriaceous; 2-keeled; wingless; 9–11 -veined. Lower glume surface convex; smooth. Lower glume apex acute. Upper glume ovate; gibbous; 1 length of adjacent fertile lemma; chartaceous; without keels; 9–11 -veined. Upper glume apex acute.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret ovate; 1 length of fertile lemma; hyaline; 1 -veined; without lateral veins; acute. Fertile lemma gibbous; membranous; 3 -veined. Lemma apex acute. Palea hyaline; without keels.

FLOWER Anthers 3; 3–4 mm long. Stigmas 2.

DISTRIBUTION Asia-tropical: Malesia.

NOTES Andropogoneae. Koning & Sosef 1996.

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