I have an idea for a world:
Let's suppose that there is a tree that evolves a weird sort of flower: when the bud opens, instead of revealing the usual flowery bits, it reveals an animal-like entity that acts as it's gametophyte. This animal-like gametophyte (let's call it a faerie), after reaching maturity, leaves the parent tree and searches for a compatible mate. Once the mate is found, the two faeries sexually couple and fuse into a sporophyte sapling that eventually matures into a new "faerie tree", ready to produce new faeries.
My question is:
Would it be possible for faeries to develop sentience, or even humanoidism, and if so, how would it work?
And if they develop human level intelligence, how would the fact that sex results in the death of the faeries involved at the expense of the tree (which is basically non-sentient) affect faerie culture?
And going backwards a bit, how would animal-like gametophytes even evolve in the first place?