The thought occurred to me, Dave (after chalyse made the suggestion of duplicates), that maybe such a feature wouldn't be too hard to implement.
As I recall, you recently made a fix/change to the code, to check for people accidentally adding duplicates to their plant lists. (Yeah, that was me...
) Instead of automatically disallowing that option (as you do now, with a flag to the user that they already have that plant), you could instead make a modification to the code, along the lines of:
If user-has-plant = true (this is something you have already determined)
then ask-user-if-wants-dupe (this is a subroutine that pops up a box to ask the user; depending on what button/link they click, returns a value of true or false)
If user-has-plant=false OR user-wants-dupe=true
then add-plant;
My programming skills are quite rusty but it seems like something like that might work. It is then up to the user to manage their duplicate plant entries (one they can comment as a diploid, the other as a tetraploid).
This (for my taste) would be Plan B; ideally there should be a way to add Tetra (whatever) as a new plant to the database, because (apart from the ploidy) I suspect that there are probably other plant differences (flower size and scape height, at least).
