An alchemic stone

So, too, the matter of the Stone shews most beautiful colours in the production of its flowers. The comparison, also, is apt, because a certain matter rises out of the philosophical earth, as if it were a thicket of branches and sprouts: like a sponge growing on the earth. They say, therefore, that the fruit of their tree tends towards heaven. So, then, they put forth that the whole thing hinged upon natural vegetables, though not as to its matter, because their stone contains within itself a body, soul, and spirit, as vegetables do.
from The Aurora of the Philosophers by Theophrastus Paracelsus