"Travis,I just took a look at The Kew List, and all former species of Chionodoxa have been moved to Scilla. And more than the two you mention are retained as species, just as Scilla and not as Chionodoxa. Jim McKenneyMontgomery County, Maryland, USA, USDA zone 7, where I cross pollinated Merendera sobolifera and Colchicum ?hungaricum yesterday: wish me luck!" Jim, This is true, and independent phylogenic studies have justified the inclusion of Chionodoxa into Scilla sensu latissimo (although it is pretty clear that Chionodoxa is morphologically distinct). Whatever they are called, it is still difficult to tell the species apart, especially for the amateur like me. It doesn't help that the names are mixed up by bulb sellers. The two keys I have found were mostly reliant on characteristics that rely on a basis for comparison (like, for example, two different species to compare side by side). I am pretty sure I'm onto something with the differences of the filaments of at least some of the species. C. luciliae (Scilla luciliae) has filaments of unequal lengths, not tapered; C. forbesii (Scilla forbesii) has filaments of equal length and are usually tapered. Other species may be similar, and can be divided into groups (C. nana in "Luciliae" group; C. sardensis into "Forbesii" group). But I've only observed a small number of plants, so I'm not really sure. I doubt it has any taxonomic value anyway, this is just for the gardener (and myself) to be able to see a single flower and know what it is. Besides, taxonomy apparently doesn't care about physical characteristics any more and is instead in favor or DNA analysis to decide what plants should be called. As Jack Horner put it (TED Talks: Where are the baby dinosaurs?), "Scientists like to name things". Travis Owen Rogue River, OR amateuranthecologist.blogspot.com