What follows are photos of some of the snowdrops I saw and which will hopefully give you an indication of these differences.
G. Elwesii, named for Henry John Elwes who 'discovered' it in Turkey and who lived at Colesbourne Park
Contrasting G. Elwesii, taller, at the back, and G. Nivalis, the common snowdrop, in front.
G. Elewesii Mrs McNamara
G. Hill Poë
G. Lapwing, which I was very taken with. The markings made me giggle as I thought they looked like skull and crossbones!
G. St Annes
G. Lord Lieutenant
G. nivalis Viridapice
And, a carpet of snowdrops.
G. nivalis and eranthis hyemalis
I picked up Galanthus Lapwing, of which i was particularly taken and at £15 was the most expensive snowdrop I've ever bought. I'm putting this in a pot to see if I can bulk it up over a couple of years, before planting it out. I also obtained the double Galanthus, Titania, and Iris histrioides 'Lady Beatrix Stanley'.
I noticed them selling Galanthus nivalis f. pleniflorus 'Bagpuize Virginia', of which I have about 15 now, for £20 each! I had no idea they were worth that much. For me they are a happy reminder of regularly visits to my favourite Oxfordshire snowdrop garden at Kingston Bagpuize.
Colesbourne Park will be open for three more weekends for the 2015 snowdrop season if you would like to get up close and spot the differences between them yourself.