Chris Whitehouse wrote “A denomination class is a group of plants within which the cultivar name cannot be repeated - it is normally the whole genus but in a few cases such as Gladiolus, it is subdivided so that you can have the same cultivar name in Gladiolus as long as it belongs to a different denomination class.” Thanks, Chris. Your comments about denomination classes might have particular relevance to my query because as I mentioned in an earlier post I have seen the cultivar name ‘Halley’ in a catalog from the 1920s used for a glad which might or might not be the same one I am growing. The catalog in question does treat primulinus hybrids separately, and the cultivar it lists as ‘Halley’ is not placed among them. I hope there are others who can shed more light on this. Jim McKenney jimmckenney@jimmckenney.com Montgomery County, Maryland, USA, 39.03871º North, 77.09829º West, USDA zone 7 My Virtual Maryland Garden http://www.jimmckenney.com/ BLOG! http://mcwort.blogspot.com/ Webmaster Potomac Valley Chapter, NARGS Editor PVC Bulletin http://www.pvcnargs.org/ Webmaster Potomac Lily Society http://www.potomaclilysociety.org/