Now let's just think about this,...if I'm understanding Janet and Janice correctly, The one and only source of true daffodil classification is RHS or ADS.
The 5000 other references (which include John Bryan(probably considered the world's premier bulb authority), Flora Europaea, USDA, the Plant List (which dave considers valid), KEW, the European Environment Agency, En-Nomen (Pan-European Species Directory), National Genetic Resources Program. Germplasm Resources Information Network, National Biodiversity Network, and on and on...are wrong.
