The nun orchid (Phaius tancarvilleae (Banks ex L'Héritier de Brutelle) Blume) [fay' us tan' kar vill' ee ay] is a wetland species native to China, India, Indonesia, Malaysia, and the east coast of Australia. It is considered easy to grow from seed and has naturalized in some of the Caribbean and Hawaiian islands and is recorded growing in at least one wetland in Hardee County, Florida.

In Australia, the plant is called the swamp lily or swamp orchid where it is listed as endangered due to loss of habitat. In the U.S., this reliable bloomer is known as the nun orchid for the shape of the column (the floral structure consisting of the style and stamens). Somewhat fancifully, the column resembles the hooded head of a nun bowed in prayer.

The generic name, Phaius, is from the Greek, phaios, meaning dusky for the brownish color of the tepals. The plant was introduced to European gardeners by Dr. John Fothergill in 1778 and originally named Limodorum tancarvilleae by Joseph Banks in honor of Lady Tankerville in 1788. For purposes of Latinizing the name, it is said the species designation goes back to her family home in Tancarville, Normandy, France.