Karl Wilhelm Ludwig Pappe (1803 in Hamburg – 14 October 1862) was a German-born physician and botanist who lived and worked in Cape Colony.

He qualified in medicine in 1827 with a thesis on the flowering plants of Leipzig, "Enumerationes plantarum phaenogamarum lipsiensium specimen".

[2] He travelled to Cape Town in January 1831 and was registered as a physician, surgeon and accoucheur (a male obstetrician).

He joined the South African Medical Society in 1832 and was one of three doctors in charge of the temporary hospital in Cape Town during the measles epidemic of 1839.

He published "Systematische lijst van zoodanige Kaapse planten geslachten, als naar zulke natuurkundigen genoemd zijn die zich in de botanie vedienstelijk gemaakt hebben" (Systematic list of those Cape plants that have been named after naturalists who distinguished themselves in botany) in the Nederduitsch Zuid-Afrikaansch Tijdschrift (Dutch-German South African Magazine) in 1833.

[3] It was republished in 1847 as a pamphlet, "A list of South African indigenous plants, used as remedies by colonists of the Cape of Good Hope".

[2] In 1854 Pappe published "Sylva Capensis; or, a description of South African forest-trees and arborescent shrubs" which was a commentary on the 77 specimens sent to the Universal Exhibition in Paris in 1855.

To this end, in 1845 he wrote several letters to the editor of The South African Commercial Advertiser describing the history of the Cape garden established by the Dutch East India Company.