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.

Coix gasteenii

HABIT Perennial. Rhizomes elongated. Culms 100–180 cm long. Leaves cauline. Ligule an eciliate membrane; 0.3 mm long. Leaf-blades 9–150 cm long; 10–23 mm wide. Leaf-blade surface papillose.

INFLORESCENCE Monoecious; with a male and a female inflorescence subtended by the same spatheole. Synflorescence compound; paniculate. Inflorescence composed of racemes; axillary; deciduous as a whole; subtended by a spatheole; exserted (male), or enclosed (female). Spatheole ovate; 0.5–0.7 cm long; indurate. Peduncle straight; widened at apex; disarticulating; disarticulating below uppermost sheaths.

Racemes 1; single; bearing a triad of spikelets. Rhachis obsolete.

Spikelets in threes. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 2 in the cluster. Male spikelets sessile and pedicelled; 3 in a cluster. Pedicels linear; 1 length of fertile spikelet.

STERILE SPIKELETS Companion sterile spikelets represented by barren pedicels.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; 7–9 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes dissimilar; reaching apex of florets; similar to fertile lemma in texture. Lower glume ovate; 7–9 mm long; 1 length of spikelet; membranous; firmer above; without keels. Lower glume apex acute. Upper glume ovate; membranous; firmer above; with hyaline margins; 1-keeled. Upper glume apex acute.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret ovate; 8–9 mm long; 1 length of spikelet; membranous; firmer above; acute. Fertile florets female. Fertile lemma lanceolate; 6–7 mm long; membranous; firmer above; keeled. Lemma apex acute. Palea hyaline; 2 -veined; without keels.

FLOWER Anthers 3. Stigmas 2; terminally exserted; papillose. Styles connate below.

FRUIT Caryopsis with adherent pericarp; 4–5 mm long. Disseminule comprising a inflorescence.

MALE Male inflorescence unlike female; a single raceme (1.4–1.8cm, exserted). Male spikelets distinct from female; 2 flowered; ovate; 6–7 mm long. Male spikelet glumes 2; wingless; muticous. Male spikelet lemma 9 -veined; muticous.

DISTRIBUTION Australasia: Australia.

NOTES Andropogoneae. Simon 1993.

ADDITIONAL CHARACTERS Spatheole bearing a blade.

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