Euphorbia mesembryanthemifolia is a species of flowering plant in the spurge family (Euphorbiaceae). Common names include seaside spurge and coastal beach sandmat; Spanish: alfombra de arena costera, lit. "coastal sand carpet". It is native to the Western Hemisphere, where it is found in coastal areas from Florida in the United States south to Colombia and Venezuela, as well as in Bermuda and the Caribbean. Its natural habitat is on beaches and rocky shores.