Eleutherine is a genus in the Iridaceae family related to Tigridia. It is common in dry grasslands in subtropical areas of South America and will need a warm climate to thrive.
Eleutherine bulbosa, from Argentina via Plant Delights Nursery. Flowers 3 cm in diameter open in the evening and are scented, but are completely shriveled by morning. Photos taken July 2004 by Lee Poulsen.