Pete is correct...and their difficulty in growing has a lot to do with recovery...unlike many multiflorals (roth , parishii, etc), they take a much longer time to recover from a lapse in culture or stress ..so many people kill them if they have small seedlings...i am well stocked in sanderianum plants from a compot to various growth stages up to multigrowth plants but have yet to bloom one on my own...i have found the hybrids to be fascinating examples of genetic diversity..i suppose it's an obsession (fer sure) but waiting years for a each plant to acquire significant growth becomes frustrating...finding a blooming sanderianum, to me, is a find of a lifetime, especially one with good color.