Phytologia (November 1991) 71(5):420-422. NEW COMBINATIONS IN POTENTILLA AND HORKELIA (ROSACEAE) IN CALIFORNIA Barbara Ertter University and Jepson Herbaria, University of California, Berkeley, California 94720 U.S.A. ABSTRACT Three new combinations are proposed for use in the upcoming re-vised Jepson Manual of California plants. Potentilla rimicola (Munz k. I.M. Johnston) Ertter replaces P. wheeleri subsp. rimicola, while Horkelia californica subsp. dissita (Crum) Ertter and subsp. fron-dosa (E.L. Greene) Ertter replace H. elata and H. frondosa respectively. KEY WORDS: Potentilla, Horkelia, Rosaceae, California, taxon-omy As a result of preparing the treatment of herbaceous Rosaceae for the forthcoming The Jepson Manual: Higher Plants of California, several new combinations were found to be necessary. Key characters and descriptions will be found in the Manual and are therefore not included here. Potentilla rimicola (Munz & I.M. Johnston) Ertter, comb, et stat. nov. BASIONYM: Potentilla wheeleri S. Wats. var. rimicola Munz & I.M. Johnston, Bull. S. Calif. Acad. Sci. 24:18. 1925. The Potentilla wheeleri complex (Rydberg's Subviscosae) includes a series of biogeographically interesting taxa on isolated mountain ranges in Cahfor-nia, Arizona, New Mexico, and northern Mexico. Typical P. wheeleri occurs from the southern Sierra Nevada to northern Baja California. Although the distinctiveness or circumscription of possible segregates var. paupercula Jep-son (Mount San Gorgonio, San Bernardino County, Cabfornia), P. luteosencea Rydb. (northern Baja California), or P. viscidula Rydb. (southern Arizona) are thus far uncertain, my initial studies of the complex indicate that at least var. rimicola is worth recognizing at the species level. A new combination is therefore needed at this time for the Jepson Manual. 420
BioStor
