Lectotypes are designated for the following species of Quercus (Fagaceae) and associated synonymous taxa collected in Mexico, and what was later to become California, during the historic five-year Malaspina Expedition around the world: Quercus agrifolia, Q. castanea, Q. diversifolia, Q. elliptica, Q. lobata, Q. lutea, Q. magnoliifolia and Q. rugosa as well as Q. kelloggii and Q. tinctoria var. californica collected by early collectors in California.