Amaryllis is the type genus for the family Amaryllidaceae. Although it is the common name used for hybrid hippeastrums which are found on the Hippeastrum Hybrids page, there are actually only two species in this genus and one of them was only recently discovered. Both are found in the winter rain area of South Africa.
Amaryllis belladonna, known to many as "Naked Ladies" because the flowers are pink to white and bloom before the leaves develop, is found in loamy soils in seasonally moist sites in the Cape Floral Province. It has a great variation in time of bloom, starting in summer and extending into fall. It has naturalized in many mediterranean climates throughout the world and is especially popular in California.
A second species, named Amaryllis paradisicola, was described in 1998. It is not in general cultivation. A short description and link to a photo can be found here.
There have been many discussions on the PBS list about how to get Amaryllis belladonna to bloom. Members living in Mediterranean climates are much more likely to get it to bloom. People have said the bulbs need to stick out of the ground and they have also said they need to be covered. Some summer water may help, but you also hear a dry dormancy is helpful. Plants in the ground bloom better than plants in pots and plants growing in the sun are much more likely to bloom than ones in the shade. One factor that influences blooming in the wild is fire. After a summer fire, there is usually good bloom in the fall in the wild. In September 2009 a restaurant burned to the ground in northern California denuding the slope below which was covered with low growing vegetation. Several weeks later spikes were appearing. It's hard to know when or if these bulbs were planted since the slope is steep and it would seem to be impossible to plant them. The photos from Mary Sue Ittner don't really capture how steep the slope is since I had to take the pictures with my zoom lens from the bottom. The third picture was taken the following month when more flowers were open. In 2012 the slope is now covered with non native weedy vegetation and the plants are no longer flowering.
An article in Veld & Flora magazine described the plants' strong response to fire in the wild, and speculated that they bloom more frequently in cultivation because weeds are removed from around them. The article has been reproduced here.
The first photo by Bob Rutemoeller shows some in bloom September 2004 on the Mendocino coast in northern California. Photos 2-4 are by Nhu Nguyen. Photo #2 is from a yard in Berkeley, CA and #3 from the UC Botanical Garden showing these plants blooming dramatically en masse. The plants from the UC Botanical Garden bloomed in an early year in mid July, 2008. Photo #4 is a closeup.
Many Amaryllis selections have been made, and the species has also been hybridized very heavily with related genera for more than a century. To learn more about the history of some of these hybrids, read this conversation between David Sneddon and Jim Lykos, two Australian members of the PBS list. An example of these is xAmarcrinum, a hybrid between Amaryllis and Crinum. See also xAmarygia.
The late Les Hannibal was a longtime breeder of Amaryllis hybrids. Over a period of several decades, he tossed all of the excess seeds from his breeding program into the roughly one acre backyard of his home in Sacramento, California. The result was a sloping hill covered in many thousands of bulbs, scattered everywhere and even leaking into the neighbors' yards. When in bloom it was a remarkable sight, a kind of fairyland of bulbs. Shortly before his death, Mr. Hannibal permitted several people to collect bulbs from his yard. Photos and descriptions of some of those bulbs dug by Michael Mace can be found on Les Hannibal Hybrids 1-25 and Les Hannibal Hybrids 26-48.
Amaryllis hybrids generally range in color from pure white to pink to a mauve color that can look reddish in photos. The examples below give some idea of the range of colors and shapes.
Amaryllis seeds also vary from dark pink to white, as shown by the photo below. They can also be variously veined and mottled. The seed color doesn't necessarily predict the flower color, though -- pink seeds turn darker when exposed to sunlight. Pure white seeds do seem to be associated with white flowers, although we haven't heard of a controlled test of that.
The flowers also vary in size, time of bloom, color patterns on the flower, shape of flower, etc. The photos that follow give some idea of the variety available.
MBQ 01 is an Amaryllis hybrid from Richard Doutt's old Bio Quest International mail order nursery, purchased from him in the early 1990s. It blooms reliably, at the end of summer. It's very vigorous, has a good bud count, strongly radial form, makes offsets regularly, and has large, reasonably dark pink flowers (they start pink and white, and then age to more or less solid pink). Unlike some other dark pink Amaryllis hybrids, these are pure clear magenta, with no mauve overtones. Photos by Michael Mace.
Photo 1 below taken by Doug Westfall is of a selection he received as 'Old Wine #1'. Photos 2-3 by Mary Sue Ittner and Bob Rutemoeller show a couple of the ones received from the dig made by Michael Mace of Les Hannibal's hybrids.
Paul Tyerman offered seed of some of his multiflora hybrids. Below are three pictures of a hot pink one including the bulb with the stem emerging, close up of the flower, and the flower head. The last picture is of a white one with pink tips.