While Carrizo Plain (California, USA) is a hotspot for rare and endangered species, little effort has been made to sample the lichen flora of the Plain. To assemble a preliminary checklist of lichens from the basin floor of Carrizo Plain, we sampled along a transect from the basin's alkali complex to its western edge, as well as from clay slickspots with high sodium content, and a rocky site in the eastern Plain. We document a substantial lichen flora on the Plain and note several collections that were the first record for a species in the region: five species were the first in San Luis Obispo County, and nine were the first for the San Joaquin Desert. We include notable collections and observations on potential ecological patterns and highlight Carrizo Plain as a promising hotspot for research on lichen ecology, particularly for species adapted to extreme environmental conditions.