Fritz Schäfer (or Schaefer) studied medicine at several German universities and qualified as a medical practitioner in 1905. A medical dissertation by him, Zwei Fälle von Lymphosarcom des Herzens (20p) was published in Greifswald in 1911.
From 1909 to 1911 Schäfer was a medical practitioner on the Lüderitz-Keetmanshoop railway in German South West Africa (now Namibia). He collected plants mainly in the Klein Karras area. His specimens were sent to the Botanischer Garten und Botanischer Museum in Berlin, Germany. Several species were named after him: Celosia schaeferi (by H. Schinz*), Zygophyllum schaeferi (by H.G.A. Engler*), Ferraria schaeferi (by M.K. Dinter*), Manulea schaeferi, Ammannia schaeferi, Ceraria schaeferi and Lycium schaeferi.