Jon, I do not know the name of the large yellow calla other than what I get in as a cut flower. They come from Calla Co./Callafornia Calla. They have a web site but the photos do not make them look as big as they actually come. I do believe they are technically a mini calla but it looks like it is on steroids. They are about 3/4 the size of a full grown aethiopica. John Ingram in Camarillo, CA, between Santa Barbara and L.A. http://www.floralarchitecture.com/ "Your Clivia Connection" New number >>> 805.914.9505 (cell, west coast time, please call accordingly. Thank you)