Good question, I can't give you a specific list just off the top of my head, It may be due to individual variations and cultural practices more than particular cultivars. According to Veronica Read, 'Hippeastrum, the Gardener's Amaryllis' published by the RHS, all Hippeastrum are evergreen. Common cultural practices (decreasing day length, decreasing temperature and decreasing soil moisture) force dormancy both to ship dormant bulbs and to time out blooming. Blooming is triggered by increasing day length, increasing temperature, and increasing moisture, whether or not the bulbs have previously lost their leaves. I have heard antidotal accounts of some of the small flowered cultivars and some of the cybister forms tending to be evergreen. This is a fascinating subject and I would like to hear others' experiences.
