In 1898 he met Andreas Schimper, renowned botanist and phytogeographer, who had arrived aboard the "Valdivia". Together they made collecting trips to the Montagu and Swartberg passes, and then further to Knysna. Schimper died in 1901 before his report was written, so that Marloth was asked to write an account on the phytogeography of the Cape. In those times "the Cape" was interpreted to cover a large part of southern Africa. In order to write the report, Marloth felt it necessary to make extended trips to the Cederberg, Gifberg, Koue Bokkeveld, Swartruggens and on to Rhodesia.