Coix lacryma-jobi (Job's-tears).
Coix lacryma-jobi is a grass indigenous to Southern and Eastern Asia that has been introduced in tropical and warm temperate regions as a cereal, fodder and forage crop, and for its attractive grains which are used as beads for making rosaries, necklaces, and other objects. It has escaped cultivation and become naturalized in more than 90 countries, often occurring as a weed in humid and disturbed sites, along waterways and forest edges, wetlands and swamps. C. lacryma-jobi is a robust grass that grows forming dense and tall clumps that block the flow of waterways and outcompete native vegetation. It is listed as invasive in Singapore, Australia, New Caledonia, the Cook Islands, the Galapagos, Greece Hawaii, French Polynesia, Mexico, Brazil, Nicaragua, Costa Rica, Puerto Rico, the Virgin Islands, Jamaica and on many islands in the Pacific and Indian Ocean. It is regarded as potentially invasive in the Mascarene Islands (Mauritius, Reunion and Rodrigues).