Plateland Crystals

Plateland crystals split from their ancestor the Dome Crystal. The shell symbiont had through mutation lost some of its developmental organization, resulting in the failure to form the densely arranged supportive middle layer that many crystals rely on for structural support. This inability to form their distinct rigid faces and tower quickly lead to selection of those with growth habits that took advantage of a sprawled body form, which eventually became more sheet-like.

Body Form
Having lost the dense supportive layer inside it, the shell symbiont is far less demanding in materials for growth, and their internal arrangement has now opted for a more airy design. The tissues grow in springy arches or bubble-like formations. This results in a lot of empty space while also allowing for a body that can bounce back from getting stepped on.

This flattened form also had a significant affect on the internal red symbiont. The increase of surface area had resulted in a decreased volume consequently occurring. This meant a loss of a significant amount of red symbiont biomass. Unlike in its ancestor, the central core directly associated with the shell is a simple single sheet of tissue. The filaments extended up and out from the red tissue, used to interface the two symbionts, are able to reach throughout the entire shell and even extend to the surface. Often the red tissue may be slightly exposed from underneath due to the rippled nature of plateland crystal bodies. This rippling is due to different growth rates toward the center of the organism, both on its own and in response to external stimuli. Beneath the organism its roots are thin and cord-like, with mycelioid body thoroughly coating and spreading out from them.

Growth Behavior
Growing flatly, while being a relatively thick obstacle, proved highly successful in the realm of competition. Sprawling across the ground immediately seized territory from other would-be colonizers, and growing outward pressed them against more delicate purple and black flora promptly pushing them over to be smothered and turned into soil. Though not a winning strategy in the wake of true shrubs and trees, it had granted the plateland crystal a domineering relationship with smaller unlignified or unhardened flora when butting heads. This has given rise to new plateland habitats: open areas densely carpeted with layers of flat crystal flora and dotted with the occasional tree or speckled with black or purple flora that managed to find cracks in the chitin flooring of their home.

Symbiosis
One other form of flora that does quite well in these habitats are Marbleflora. These simple little purple balls readily colonize the rather flat surfaces of the crystals to enjoy a comparatively competition-free habitat. This colonization is approached in various fashions by plateland crystalshells may respond by growing in a manner that shuttles the balls into crooks, others dimple beneath them, while some of the largest and most successful forms take this to an extreme and literally grow thin layers on top of the purple flora to create holding chambers, in much the same manner as their internal empty spaces. These blisters tend toward translucence due to their thinness. All responses, however, lead to an increased proximity between the marbleflora and the internal red symbiont.

It is through this corralling that the marbleflora become a form of livestock to their landscape. Dorsal mycelioid hyphae spawn outward, exposed, from embedded filaments to infiltrate and consume the marbleflora. Smaller species with less surface area to spare will perform this quickly, as a means to clean themselves before becoming recolonized. Larger species with deeper channels and greater faces will consume them with leisure, the marbleflora budding making up for lost members of their flock. The blister forming species completely encase their stock, this removal from the outside world ends up protecting them from herbivores and the division of their group prevents disease from spreading. The blisters also mean that no red symbiont ends up completely exposed on the upper surface.

Despite forfeiting the dense supportive layers inside their shells, which would have provided them upright stature, the plateland crystals are still Crystal Flora and so have cell walls of chitin. This makes them more nitrogen-hungry than other flora that rely only on cellulose. To fulfill this need the crystals allow Nitrocycle microbes to colonize throughout spaces inside the green shell symbiont. Inside these tiny pockets they are safe from microbial predators and the elements, the only thing keeping them in check being the red symbiont filaments that consume them as they multiply. It is in this way that the microbes become a direct nitrogen source for their host. The microbes in turn prefer colonizing most densely near the contact points between the two symbionts where nutrients is exchanged, sapping off whatever they need to proliferate.

Reproduction
Reproduction is comparable to their ancestors, with a hollow or cavity forming beneath their green surface and into the red core. Most species however, unlike their ancestor, create a single large off-center hollow rather than many small ones. This hollow fills with spores of both the green shell and red core symbionts. As it matures and fills the hollow comes under pressure and a visible mound appears in the organism, the face of the crystal above develops a faceted appearance as well. Once the hollow can no longer hold the facets above will split and unfurl at once as the hollow ruptures to release the airborne spores. These ruptured areas become dettached and discarded from the organism to decompose, resulting in a deeply lobed body with a permanently altered growth pattern. Hollow formation typically occurs during Winter in temperate regions or dry seasons where daylength change is minimal. Spore release often happens at or shortly before seasonal transition.

Environmental Influence
Plateland crystals can be considered early secondary succession organisms, preferring areas with already established soil and lacking heavy populations of competition. The exception to this is in established plateland environments where spores will readily colonize with complete disregard for their mature relatives. Much like oysters of Earth growing on top of one another, the crystals will layer as they establish, with baby plateland crystals surviving on rain and dust that settle into the dimple indent they've ended up in on the adult. The new generation remains quite stunted until a snaking root taps the soil found hidden beneath. Once it accesses groundwater growth increases rapidly, the tiny babies overgrowing the plates beneath them, and the generation before them becoming smothered as they're forced to become a lower layer.

As the years pass the light will be sealed away from the lower layers by the new growth above and their green symbiont starved to death. The red symbiont may survive for a while longer without it, but isn't designed for surviving on its own nor in the low oxygen environment it creates for itself and eventually suffocates. At this point the nitrocycle microbes are able to run rampant, as the body of the crystal still acts as a barrier even during early decomposition, further increasing the nitrogen contents of their deceased host as they themselves consume it for energy. Advanced decomposition however exposes them to predatory soil microbes which end up depleting the populations in the lowest layers. Because of this process the soil beneath platelands can actually be quite rich and a boon for any flora that manages to take root through the many flakey layers of decomposing crystal.