Coix

Coix is a genus of Asian and Australian plants in the grass family.

The best-known species is Coix lacryma-jobi, widely called Job's tears. Its variety Coix lacryma-jobi var. ma-yuen is cultivated in many warm regions as a source of food, medicine, and ornamentation.

The generic name is from Ancient Greek κόϊξ (koix), which originally referred to the doum palm (Hyphaene thebaica); the fruits of the doum palm resemble the diaspores of Coix.

Species

 * Coix aquatica Roxb. - China (Yunnan, Guangdong, Guangxi), Indian Subcontinent, Indochina, Peninsular Malaysia; naturalized in New Guinea
 * Coix gasteenii B.K.Simon - northern Queensland
 * Coix lacryma-jobi L. - China, Indian Subcontinent, Southeast Asia; naturalized in other parts of Asia as well as in southern Europe, Africa, the Americas, and various oceanic islands

Formerly Included
see Chionachne Polytoca Tripsacum • Coix angulata - Tripsacum dactyloides

• Coix barbata - Chionachne gigantea

• Coix crypsoides - Chionachne gigantea

• Coix dactyloides - Tripsacum dactyloides

• Coix gigantea J.Koenig 1788 not J.Koenig ex Roxb. 1932 - Chionachne gigantea

• Coix heteroclita - Polytoca digitata

• Coix koenigii - Chionachne gigantea

• Coix sulcata - Chionachne punctata

Formerly included in
This genus was formerly placed in the Maydeae, now known to be polyphyletic.

Proteins and expression
Members of this genus produce their own variety of α-zein prolamins. These prolamins have undergone unusually rapid evolutionary divergence from closely related grasses, by way of copy-number changes.