The University of California maintains a Perseae germplasm collection at both the South Coast Field Station in Irvine, and a greenhouse collection at U.C. Riverside. The mother plantation accessions were collected in Mexico, Central, and South America by George Zentmyer, and planted at the South Coast Field Station beginning in 1958. The active germplasm collection housed at U.C. Riverside is a source of propagation material for international exchange between researchers studying the behavior of varieties in different growing areas. Many of the accessions in this collection were grown from seed collected from trees in the origional base collection, some were collected by Dr. Scora in Central America, and several were received from other researchers. In the table below the years in brackets (1958) are the dates these varieties were collected.