Dietes is a genus of six rhizomatous plant species of the iris family Iridaceae, first described collectively in 1866.

A few others—primarily Dietes bicolor, D. grandiflora and D. iridioides—have become popular gardening and landscaping plants around the world, and have thus inevitably naturalised in areas outside of their natural range, including across much of the Americas, from the United States (Alabama, Florida, Georgia, Hawaii, Louisiana, Mississippi, Nevada, South Carolina, Southern California and the Bay Area, Texas) through Mexico and much of Central and South America, Bermuda, the Bahamas, Hispaniola and Jamaica.

[1] Elsewhere, these species have been documented in the Azores, the Canary Islands, Madeira, southern France, Spain, Portugal, Sicily, Israel, Istanbul, Palestine, Madagascar, Mauritius, Réunion, St. Helena, Hong Kong, Java (Indonesia), Sikkim (India), Singapore, Taiwan, and Tokyo, Japan.

They are also found in Australia (near Adelaide and Perth, and much of New South Wales, Queensland, Tasmania, and Victoria), New Caledonia and New Zealand.

D. grandiflora and D. iridioides both have white flowers marked with yellow and violet, and appear similar in photographs, but they are quite different: those of grandiflora are much larger, last three days, and have dark spots at the base of the outer tepals, while those of iridioides are small, last only one day, and lack the spots.