Gustav Karl Wilhelm Hermann Karsten (6 November 1817, in Stralsund – 10 July 1908, in Zoppot) was a German botanist and geologist.

Born in Stralsund, he followed the example of Alexander von Humboldt and traveled 1844-56 the northern part of South America (Venezuela, Ecuador and Colombia). From 1856 to 1868, he was a professor at the agricultural college in Berlin, afterwards serving as a professor of plant physiology at the University of Vienna (1868–72).^[1] In 1881, at the suggestion of David Friedrich Weinland, Karsten became convinced of the correctness of Otto Hahn's organic theory of the chondrites and, as a result, wrote an essay entitled "Die Meteorite und ihre Organismen"^[2] in which he declared his support for Hahn's theory. He died 1908 in Berlin-Grunewald.

As a taxonomist, he was the binomial author of many botanical species.^[3]

• Florae Columbiae ... 1859–1869. (Vol. 1: Digital edition / Vol. 2: Digital edition by the University and State Library Düsseldorf)
• Chemismus der Pflanzenzelle 1869.
• Deutsche Flora. Pharmaceutisch-medicinische Botanik 1880-1883; second edition 1894–1895.
• "Hermann Karsten (1851) y Wilhelm Sievers (1888): las primeras descripciones e interpretaciones sobre el órigen de las terrazas aluviales en la Córdillera de Mérida." C. Schubert. Bol. Hist. Geocien. Venez., 44, pp 15–19
• "Die Meteorite und ihre Organismen", 1881 - The Meteorite and its Organisms.^[4]