Technical Abstract: Four genera of the family Ranunculaceae are treated for The Flora of the San Juan Basin, a detailed floristic manual covering the Four Corners area of Arizona, Colorado, New Mexico, and Utah. Twenty-five species in these four genera are included; full morphological descriptions, dichotomous keys, and brief summaries of geographical and ecological distribution, economic use, and taxonomic notes are given for each of them. Two of these are invasive species introduced from Eurasia, the other twenty-three are native to the area. Two of the four genera include species that are important for ornamental horticulture in the United States. This contribution will promote the recognition and exploitation of native germplasm with considerable horticultural potential, and ensure that work on land management and monitoring of exotic species outside of cultivation will rely on accurate identification and classification of these plants.