Overnight mycostrum evolved when populations of its ancestor adapted to more forested and nutrient-rich habitat inland. It has grown more reliant on detritivory, devoting almost all biomass to extensive root networks. Individuals can survive solely on the organic soil for long periods, quickly taking advantage of openings in the canopy by sending photosynthetic sprouts that also act as fruiting bodies for asexual buds. Clearings can fill with dense patches of these sprouts within a day, only to die and be replaced by other species like crystal flora and purplestems within weeks.

While most reproduction occurs via budding and fragmentation, there is occasional exchange of genetic material between root structures via conjugation.