Nomenclature of subdivisions within Phacelia Juss. (Boraginaceae: Hydrophylloideae) reflects an update to the classification of the genus, based largely upon the structure offered in summary by Ferguson. We consider this proposed classification a continuation of efforts to better understand interrelationships within the genus and tribe Romanzoffieae Dumort., and anticipate future research offering insights into systematics of Phacelia. New names, changes in status, and combinations include the following: Phacelia sect. Baretiana Walden & R. Patt., sect. nov.; P. subsect. Bipinnatifidae (Small) Walden & R. Patt., stat. nov.; P. subsect. Cosmantha (Nolte ex A. de Candolle) Walden & R. Patt., stat. nov.; P. subsect. Cosmanthoides (A. Gray) Walden & R. Patt., stat. nov.; P. subsect. Dubiae (Small) Walden & R. Patt., stat. nov.; P. subsect. Eutoca (R. Br.) Walden & R. Patt., stat. nov.; P. sect. Glandulosae (Rydb.) Walden & R. Patt., stat. nov.; P. subsect. Humiles Walden & R. Patt., subsect. nov.; P. subsect. Lineares (Rydb.) Walden & R. Patt., stat. nov.; P. sect. Pachyphyllae Walden & R. Patt., sect. nov.; P. subg. Pulchellae (Rydb.) Walden & R. Patt., stat. nov.; P. sect. Ramosissimae (Rydb.) Walden & R. Patt., stat. nov.; P. subsect. Ranunculacea Walden & R. Patt., subsect. nov.; and P. subsect. Sericeae (Rydb.) Walden & R. Patt., stat. nov.