So - I just tried doing this with a picture of an unknown plumeria which was in one of the threads in the plumeria forum. I was going to add it to the general entry for Plumeria rubra.
When I typed 'Plumeria rubra' in the search box, it gave me about 25 options of various cultivars of Plumeria rubra, but not the general one, and certainly not the full complement of Plumeria rubra varieties. What could be causing this?
I got a similar result when I typed in 'Plumeria' by itself.

Yeah if your search matches too many items then that's going to be hard. I need to think about the solution to that.

For now the best option in that case is to just enter the PID of the plant in question.

Hetty, I usually type in the plant ID number instead of the name. For the generic Plumeria page, it's 236427 and for Plumeria rubra it's 200779.

dave zuzu