UPDATE: Please note that the question was already answered perfectly - I am not looking for additional examples
I remember that there was a sentient life form evoloved from plants in Star Control 2 game (Supox).
Is there an example of such a life form in the major well known SciFi works/franchises?
Please note that it must be
directly evolved from plants. E.g. Endervers' fathertrees on Lusitania don't count - they are a result of genetic messing by Descolada virus.
Sci-Fi works (e.g. magical trees - ala Whomping Willow in Harry Potter don't count, neither do the Arda's Ents)
Clearly sentient (e.g. Triffids don't count IMHO since I don't think they are clearly proven to be fully sentient in the books, although I could be wrong).
Preferbly, though not required, an actual species, as opposed to a single Yggdrasil (well, I am not sure if Yggdrasil is sentient anyway, and it's not Sci-Fi to boot)