You would be surprised, the outer petals are some windscreen variant, I cant quite tell the second inner, but the inside looks like a mimifigure whip.
Ive assembled a couple of the botanical sets, the succulent and cactus ones have some very clever uses of standard pieces, I don't believe its often they introduce new ones
I just built this set the other day! It looks really nice, and there are some really cool pieces being used (like the minifig whips used as the center petals). It is a little repetitive because you're building multiples of each rose type, but they at least have a few variations so it's not just the same thing the entire build.