Two or three years ago I was contacted and asked if I would be interested in exchanging some bulbs for bulbs of Hippeastrum nelsonii. Well, I didn't hesitate for one second and the bulbs arrived in very good condition. They were not mature, and this year they have bloomed for the first time, each bulb sending up one or two beautiful flowers.
This lovely species is native to Bolivia, as are many very desirable bulbs. It is known from only three locales, all at low elevation, and is evergreen, said to bloom in the spring, but mine are in bloom now in January. I have been growing it in my standard Hippeastrum mix and keeping the bulbs on my heated benches. The benches are kept at about 63F and can be seen here: http://thebulbmaven.typepad.com/the_bulb_maven/greenhouse-tips/page/2/ I should add that I am no longer using perlite in my mix, and use horticultural pumice and peat, about 65% pumice to 35% peat. In the past I could not get pumice in bulk, but now I can and I buy it by the pallet. I can't recommend it too highly for growing bulbs.