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.

Coix lacryma-jobi

HABIT Annual. Culms 90–250 cm long. Leaves cauline. Ligule an eciliate membrane. Leaf-blade base cordate. Leaf-blades linear, or lanceolate; 10–50 cm long; 25–50 mm wide.

INFLORESCENCE Monoecious; with a male and a female inflorescence subtended by the same spatheole. Synflorescence compound; paniculate; prophyllate below lateral spikelets (female inflorescence). Inflorescence composed of racemes; axillary; deciduous as a whole; subtended by a spatheole; exserted (male), or enclosed (female). Spatheole ovate, or globose; 0.8–1.1 cm long; indurate. Peduncle nodding; 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 2 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 orbicular; 7–9 mm long; 1 length of spikelet; membranous; firmer above; without keels. Lower glume apex cuspidate. Upper glume ovate; membranous; firmer above; with hyaline margins; 1-keeled; 11 -veined. Upper glume primary vein grooved on either side. Upper glume apex cuspidate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret ovate; 1 length of spikelet; membranous; firmer above; 7 -veined; cuspidate. Fertile florets female. Fertile lemma ovate; 6–7.6 mm long; membranous; firmer above; keeled; 3–5 -veined. Lemma surface with 2 longitudinal grooves. Lemma apex rostrate. Palea hyaline; 2 -veined; without keels.

FLOWER Lodicules absent (female), or 2 (male); cuneate; fleshy. Anthers 3. Stigmas 2; terminally exserted; papillose. Styles connate below.

FRUIT Caryopsis with adherent pericarp; orbicular. Embryo 1 length of caryopsis. Disseminule comprising a inflorescence.

MALE Male inflorescence unlike female; a single raceme (1.5–3 cm,exserted). Male spikelets distinct from female; 2 flowered; 8–10 mm long. Male spikelet glumes 2; wingless; muticous. Male spikelet lemma 3–5 -veined; muticous.

DISTRIBUTION Europe: southwestern and southeastern. Africa: north, Macaronesia, west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, south, middle Atlantic ocean, and western Indian ocean. Asia-temperate: Soviet Middle Asia, western Asia, China, and eastern Asia. Asia-tropical: India, Indo-China, Malesia, and Papuasia. Australasia: Australia. Pacific: southwestern, south-central, northwestern, and north-central. North America: southeast USA and Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Andropogoneae. FTA.

ADDITIONAL CHARACTERS Male raceme erect; spatheole bladeless.

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