Daylily Database
The American Daylily Society maintains a database of over 82 thousand daylilies (yes, 82 thousand). You can search by daylily name, partial name, and hybridizer; or run an advanced search on ploidy, season, flower form and many more attributes.
Search results include many helpful details on your daylily, including: registration year, parentage, and notes about the flower's form and color. Here's an example result showing details for the 2015 Stout Medal winner:
