Ben, All the material I have read on the justification of moving Chionodoxa into Scilla references Scilla bifolia group as being the closest relatives (or the synonym S. nivalis) and also compare seed morphology (Franz Speta did this, I think). It seems the classification of Scilla (and close relatives) is confusing and contradictory. Different authors over the last 100 years ha be classified and reclassified the genus many times based on different morphological traits such as: Leaves, seeds (elaiosome present or not), seed capsule, bulb characteristics, and even seedling traits, not to mention flowers. It seems flower differences were the last morphological characteristics used, the main determinants of Scilla vs. Chionodoxa. However the recent trend has been molecular studies comparing chromosome counts, protein markers, and the ability for species to hybridize. I have some papers that explain it better than I can, if you want I can email them to you. Travis Owen Rogue River, OR amateuranthecologist.blogspot.com