A delightful set of ruses.
For a game on iPad, Fates Forever sure looks lush. It manages that by using as many tricks as possible to use the fixed-angle camera view to reduce the geometry complexity of the foliage.
The neatest trick they manage is the ground plane. All those plants on open ground right next to the path are actually just baked into the texture and are part of the ground plane.
Most of the other plants are just a texture on a card angled towards camera, but some clever texture work gives them perspective and depth. With some aggressive asset reuse I imagine they can fit a lot of plants into just a few texture sheets.
These tricks operate on the same principal as those sidewalk chalk pictures: they look 3D from the designated angle, but the illusion breaks if you were to just rotate the camera a bit. Thankfully this is video games, and you can control what angle the camera is set to.
Fates Forever (2014)