Crustose lichen communities are part of the aesthetic appeal to visitors of Yosemite National Park and Sequoia National Park.: They form dark vertical drip-like stripings along drainage tracks in the rock faces, resulting in Native Americans giving the name Face of a Young Woman Stained with Tears to Half Dome.: Their tight adherence to the rocks give them the appearance of being painted on, and up close they appear as intricate multicolored patchwork mosaics.: They often completely cover the exposed surface of the rock.: They add to rock weathering.: These crustose rock lichens lack rhizenes and a lower cortex (lichen).: