Carl (or Karl) Otto Harz (28 November 1842 in Gammertingen – 5 December 1906 in Munich) was a German mycologist, pharmacist and botanist.
After spending time as an intern in several pharmacies, he studied botany at the University of Berlin. Later, he relocated to Munich, where he served as a lecturer at the Technische Universität München (from 1873) and at the Tierärztlichen Hochschule (from 1874). In 1880 he was appointed professor of botany and pharmacognosy at the Tierärztlichen Hochschule.[1]
In 1877, with pathologist Otto Bollinger, he conducted early studies of actinomycosis in cattle, and is credited for naming the causal agent Actinomyces bovis. From his observations, he believed the culprit to be a mould, related to the genera Botrytis or Monosporium.[2]
As a taxonomist, he circumscribed a number of varieties from the species Cucurbita pepo.[3] His name is associated with the following mycological genera: