Originating as a hybrid of the Crystal Bush and the Colony Crystal, the crystal grove inherits a largely “exposed” mycelial network which is now petrified and further modified into an above-ground root-like structure which allows it to stand high off the seafloor without taking up as much ground-level space; it doesn’t grow out new branches, instead new branchings of its roots forming underground and eventually surfacing. As it “stands” above other life on the sea floor, it is able to avoid too much competition from sea rupees and colony crystals which it shares parts of its environment with; however, as they still make it difficult for it to find sufficient open land to grow in, it has also developed very hardy spores which can last as long as a few years in a dormant state, allowing it to even spread to the coasts on the other side of the ocean via the ocean gyres. Because of the mineralized bone-like structure of its trunk, it cannot filter feed like the colony crystal can and relies on detritus and photosynthesis like the crystal bush; as a result, it has much crystal cover for the latter purpose. Like both ancestors, it reproduces sexually with water-borne spores.
Footnote: The crystal grove’s existence as a hybrid species despite parents being in different genera is that the parent species are very closely related (same ancestor), sexual reproduction only recently evolved and protection against hybridization has not, sessile life like plants and fungi in the real world are very tolerant of hybridization, they have the same reproductive method, and the combination of traits is not fatal to the original hybrid offspring.