From 2speccers2tools wiki

Within the landmass known as Kamm, the floral communities were just starting to develop and become unique while the faunal communities were almost non-existent. This presented some local Spiteweed species with the unique opportunity to diversify, and so they began to grow larger and larger. As they did, they needed to make some important changes to make a living and thus gave rise to the Spitebush.

Much like their ancestors, the Spitebush is a multicellular organism that gets a good amount of their energy from both photosynthesis and from taking in ambient amounts of spite from the environment around them. The large leaf-shaped appendages have become more complicated and form what you could call "branches", which increases their overall surface area for both collecting sunlight and getting more spite. The individual leaves and the other tissues of the Spitebush still contain high amounts of spite, which deters any local fauna species from eating them since they would have a horrible death if they tried. Since the species relies a lot on photosynthesis, the Spitebush is capable of growing to a relatively decent size, though this then meant support became a bit of a problem.

One way the Spitebush dealt with this was by growing a much larger and more extensive root system, which also meant a larger surface area to take in nutrients for photosynthesis. This was not enough, however, so the Spitebush also developed a sort of "trunk" with the structure being made out of chitin. Although they grow relatively slowly due to the chitin trunk, the Spitebush can start breeding relatively early on, releasing their many spore-like gametes into the air to then become new Spitebushes.