I think votes count when you contribute a remark, the first entry has to have the picture I think.
At least that is the way I read the rules:
"4. Optionally, check out the other nominations, and if you see something already nominated that you like, feel free to post a reply and say that you agree and add to the discussion. We will be looking at how many replies each nomination got to help us determine the winners."
Think this means a simple response is a vote for the entry. At least I hope so as I do think this plant deserves to be a winner, it is to me anyway.