Carl (or Karl) Otto Harz (28 November 1842 in Gammertingen – 5 December 1906 in Munich) was a German mycologist, pharmacist and botanist.
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).
[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.
[3] His name is associated with the following mycological genera: Harz also made contributions towards Schlechtendal's Flora von Deutschland.