Greatest Crystal Fortress
In another time and place, better known as the Alpha timeline, the largest crystal flora to ever live was the Crystal Solar Tower, standing an impressive 1,000 meters in height. This is worth mentioning because the Greatest Crystal Fortress, much shorter though perhaps significantly heavier, is the largest crystal flora that will ever exist in the Beta timeline.
The Greatest Crystal Fortress has reached its massive size through incredibly slow growth and the support of its mineralized trunk. It has a massive core made of solid biogenic rock, which remains long after it has died, and it can take nearly 100,000 years for it to reach full size. As its core is effectively a small mountain, secondary exterior growth can continue without it being crushed under its own weight. The exterior dome of crystals is actually the ancestral central dome, altered so that new dome growth splits inward instead of outward. The core starts out growing in a terraced pattern, similar to its ancestral growth pattern, but it becomes a smoother, more solid lump as it grows into itself and soil begins to form on its surface. Indeed, without digging deep into it, one might assume a given Greatest Crystal Fortress was simply a colony of still-massive flora growing on a small mountain, as the nature of its core genuinely causes soil to be able to form on it, and other flora can even grow within should the canopy be broken.
In order to reach its massive size, the Greatest Crystal Fortress actually produces proportionally fewer crystal leaves than its ancestor, reducing the amount of nitrogen it requires. However, this is hardly visible externally, as it has so much less empty space than its ancestor. Its core is climbable and may be populated by fauna seeking crystals or other organisms that live inside. Though its core is mostly rock in its center, there is actually a considerable amount of living tissue—specifically, its mycelium—up to ten meters deep from the top of the surface of the core. Soil formation is actually a necessary part of its growth, as it wears away at excess mineral coating and allows it to expand; however, it also causes it to be very weak in some spots. Large fauna can actually break these weak spots by walking over them, causing them to fall into a pit of mineral shards and mycelium. The mineral shards shred skin and armor, and the fortress gains a free meal. This can even occur far away from the dome itself, as the mineralized roots extend far and wide, but this is rare. This gives the Greatest Crystal Fortress a ton of extra nitrogen, as fauna are rich in this resource, and thus it has not developed any defenses against weaknesses caused by soil formation. Indeed, it instead forms optimal “pits” underneath weak spots specifically to take full advantage of them.
Because of its colossal size, the Greatest Crystal Fortress requires a lot of minerals to grow. As a result, every Greatest Crystal Fortress lies at the bottom of a huge crater-like depression in the ground ranging from 1000–2000 meters in width from all the mineral matter it has funneled towards its growth. This can sometimes be visible from space, but it usually smooths out into a vague dip due to erosion.
Notably, the Greatest Crystal Fortress consumes far more nitrogen than is released back into the environment. A single Greatest Crystal Fortress can live for over one million years, yet very little can feed on any part of it besides low-hanging leaves, and nothing exists which can return all the nitrogen it has taken in back to the environment in a timely manner once it finally has died.
Like its ancestor, the Greatest Crystal Fortress reproduces using airborne spores. These have allowed it to spread all over Hybarder. It supports many arboreal species depending on where it lives. However, this microclimate will not last long, as before long this species will be extinct, having used up much of the resources it needs to live and grow.