The genera Habranthus and Zephyranthes contain the plants we usually think of as "rain lilies". The wild species of Zephyranthes and Habranthus grow in the New World, from the Southern United States southward through Argentina.

Closely related to Zephyranthes and Habranthus is the genus Cooperia, which is submerged into Zephyranthes by some taxonomists. These genera are currently being studied using DNA. Marked revisions of the assignments of some of the species in these two genera can be expected.

Some species of Zephyranthes:

Zephyranthes lindleyana	Zephyranthes reginae	Habranthus robustus
Habranthus tubispathus texanus	Zephyranthes atamasca	Zephyranthes zegheri

Other Sources of Information

Bulbs for Warm Climates, Thad M. Howard, University of Texas Press, Austin (2001).
Bulbs, Revised Edition, John E. Bryan, Timber Press, Portland (2002).
Bulbs of North America, Jane McGary, Editor, Timber Press and North American Rock Garden Society, Portland (2001).
RHS Manual of Bulbs, John Bryan and Mark Griffiths, Eds., Timber Press, Portland (1995).

For a list of species names, see the Missouri Botanic Garden's Tropicos On-Line Database at http://mobot.mobot.org/W3T/Search/vast.html