Molten Lava, and not solid like the crust.
Plants needs mineral salts or nitrates to grow, there are much more nitrates in the roots of the plants than in the dirt so the plant will defuse out of the roots into the soil.
<span>Mosses is a simple type of green plant which does not have vascular tissue in its leaves or stems, but they have simple form of roots called rhizoids that anchored them in place. Mosses are found in moist areas and grow on forest floors by spreading out appearing as a sort of living carpet. </span>
It is because that's a place where no one lives so they're safe.
