sentences:  The genus is extinct in Africa, save for "P. indica", which survives in the fog shrouded mountains of the Canary Islands, which with Madagascar, constitute Africa's Laurel forest plant refugia.Fossil evidence indicates that the genus originated in West Africa during the Paleocene, and spread to Asia, to South America, and to Europe and thence to North America.It is thought that the gradual drying of Africa, west Asia, and the Mediterranean from the Oligocene to the Pleistocene, and the glaciation of Europe during the Pleistocene, caused the extinction of the genus across these regions, resulting in the present distribution.