The wild species of Hippeastrum grow in South America, from Peru and Brazil to Argentina. Some species of Hippeastrum:

aulicum	cybister	leopoldii	lapacense
nelsonii	parodii	reticulatum	papilio

Growing the so-called "Dutch Hybrid Amaryllis".

These bulbs bloom very reliably the first time you grow them. Thereafter, bloom will depend on you. See our suggestions for care and culture of amaryllis.

Other Sources of Information

Bulbous Plants of Southern Africa, Neil du Plessis and Graham Duncan, Tafelberg Pub. Ltd., Cape Town (1989).
Bulbs for Warm Climates, Thad M. Howard, University of Texas Press, Austin (2001).
Bulbs, Revised Edition, John E. Bryan, Timber Press, Portland (2002).
Cape Bulbs, by Richard L. Doutt, Timber Press, Portland (1994).
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