On our show schedule for our Flower and Produce show we followed what other shows do and used the term 'varieties' to describe a class containing ( I now know) different genera. e.g. Annuals (6) including at least 2 different varities
Of course if you're a botanist (as i am) this is incorrect and having never entered the flower section the night before the show I decided not to enter classes with the 'varieties' bit in them because I was so confused as to what they meant. i had intially been meaning to enter different varieties of the same genus which is how I read it. At the show it was evident that everyone else took the incorrect meaning of varieties. What do you have on your schedules and how is interpreted?
All the shows I have taken part in use the term 'varieties'. I think this is correct as 'varieties' is a division of the parent.
Thus Rudbeckia and Helianthus are varieties of Perennials.
Lemon Queen is a variety of Helianthus.
I wouldn't say that lemon queen is a variety of perennial.
Obviously terms mean different things to different people, to be exact you'd have to say different gennera but that would confuse even more.
To be more confusing most garden varieties are actually cultivars.
Most societies show under RHS rules and they suggest that the words kinds or cultivars (varieties) are used. i e rinds of bulbs would be daffodils or tulips but varieties of daffodil would be King Alfred or Carlton. Many schedules make it easy by saying 2 kinds/cultvars of daffodil which leaves it open to more entries. Acultivar is merelt a cultivated variety rather than a specie. This is all explained in the RHS show handbook.