Lithophytes

plants that grow on stones and rocks or in their crevices. Lithophytes, the first inhabitants of rocky regions and the primary agents of the destruction of rocks, prepare the soil for plants that are more particular as to substrate. Usually bacteria and algae first populate a stone, then crustate and scum lichens, then leaf lichens and mosses (which accumulate a layer of humus), and finally higher-plant lithophytes (many species of ferns, fescues, moor grasses, Campanula, juniper, and pine). Some species of lithophytes populate limestones, marbles, and dolomites; others populate noncarbonaceous, more acidic rocks.

The composition of lithophyte communities depends on the exposure and steepness of the slope, the character of the moisture and snow cover, the degree of weathering of the rock, and other factors. As the root systems of lithophytes grow, the crevices become deeper and wider, promoting the destruction of the rock and the distribution of higher plants. The term “lithophytes” is often understood more narrowly, implying only those plants that inhabit the surface of a stone (epilithic plants) as distinguished from those that actively implant themselves in the rock and destroy it (lithophagous plants) and those that populate the detritus and primary soil in depressions and fissures of rocks (chasmophytes).