Lithophytes are plants that grow in or on rocks. They can be classified as either epilithic (or epipetric) or endolithic; epilithic lithophytes grow on the surfaces of rocks, while endolithic lithophytes grow in the crevices of rocks (and are also referred to as chasmophytes).[1] Lithophytes can also be classified as being either obligate or facultative. Obligate lithophytes grow solely on rocks, while facultative lithophytes will grow partially on a rock and on another substrate simultaneously.[2]