Freelance botanist aspiration - evolve plants not recognised

Hey Crin, just by way of update, for some bizarre reason, I've since managed to evolve 4 plants, so it seems to have worked after I asked the question on the forum!! I waited for 48h  before posting anything and restarting the game multiple times, so I suppose the magic was in asking the question! It seems to be working so far, so I'm happy about that. Thank you so much for trying to help out!