A nasty kelp-like plant that grows in patches on the floor of the Sunless Sea. Its reflective patches draw in the unwary and then its prickly barbs catch and hold small creatures.=
Cave moss is technically a form of mold, but fortunately a relatively benign one given its ubiquity. Its fibers form a tough but springy mat over the surface of any organic-rich soil that accumulates deep underground.=
Deep in the infernal conditions of the magma sea, over the course of millions of years, mese crystals grow into flawless blocks that glow bright with strange energies.=
Floor fungus has no known uses. It can penetrate deeply into cobblestone constructions if an infestation gets hold, but it is difficult to transport and is inhibited by light so it hasn't spread beyond the deep caverns.=
Floor fungus produces a thin, slick film that spreads through the cracks of broken rock. Its ability to subsist on the tiniest traces of nutrients means it's found in relatively harsh underground environments.=
Flowstone is a carbonate-rich rock formation deposited by flowing water. It consists of minerals that the water dissolved earlier as it widens cracks and fissures into caves.=
Glistening strings of silk hang from the ceilings of some of the larger caverns, lit by the millions of tiny bioluminescent worms that spun them. Glow worms prey on the insects they lure and entangle with their faux starry sky - and sometimes the occasional bat or other larger flying beast.=
Glow worms can be harvested and used as a source of light but they die when exposed to light significantly brighter than themselves or when immersed in water. A colony of glow worms hung in a hospitable environment will undergo a modest amount of growth, allowing it to be divided and propagated.=
Large, dry caverns deep underground are well suited to aeons-long processes that concentrate crystalline substances in their walls. This rock is riddled with veins of the stuff.=
Monolithic crystals of this size form only over extremely long periods deep underground, in large long-lived cavities that allow them room to grow. Water and the life it hosts tend to disrupt the formation process of these crystals so they're only found in dry environments.=
Organic material accumulates in the enlarged pores of rock rot, but not enough to be considered "soil" in the usable sense.=
Pebble fungus grows in soil that is rich enough for farming.=
Sand scum is a crust of algae that sometimes accumulates on wet sand deep underground, somehow managing to eke out a meager living from the phosphorescent light emitted by other organisms.=
Sand scum is useless. You can get sand out of it, at least.=
Soil that is rich enough to support gigantic mushrooms can support innumerable smaller ones as well. Pebble fungus is a prolific form of mushroom that covers the soil in small spheroidal fruiting bodies.=
Spongestone is the result of advanced rock rot in its ultimate form. The stone has become so riddled with pores and cavities that it's no longer really stone.=
Stillworm grows in soil that is rich enough for farming.=
Stillworm is not actually a kind of worm, but a sort of fungus that looks uncannily like pale, motionless earthworms intertwined with the soil.=
The iconic stalactites and stalagmites found in caverns are composed of flowstone (or 'dripstone' in the case of these formations). Moist dripstone is still undergoing growth, whereas dry dripstone is found in 'dead' caverns once the source of water that created them ceases.=
Traces of Mese must have been dissolved by the water as this crystal has an inherent glow to it. Not enough Mese to be useful as a reagent, unfortunately.=