Batsch discovered almost 200 new species of
mushrooms, including
Clitocybe nebularis,
Calocera cornea,
Paxillus involutus, and
Tapinella atrotomentosa. He was a recognised authority writing two books on the topic,
Elenchus Fungorum (
Discussion of Fungi, between 1783 and 1789), which is still highly rated today and
Versuch einer Anleitung zur Kenntniss und Geschichte der Pflanzen (
Attempt at Instruction in the Knowledge and History of Plants, between 1787 and 1788).
Versuch einer Anleitung... looked into the nature of what we now know to be
fungal diseases of plants (such as
Dutch elm disease), but without realizing their origin. Rejecting the system of
Carl Linnaeus, he began to classify plants on the basis of their external form and shape and to make them generally understandable by means of a clear, precise representation, as best known in his three volume
Elenchus Fungorum.While well versed in the
flora of the Jena area, the weakness of his system lay in his lesser familiarity with the plants of the rest of the world. Other works include
Dispositio Generum Plantarum Jenensium Secundum Linnaeum et Familias Naturales, Jena 1786, generally referenced as Dispos. Gen. Pl. Jenens., alternatively titled as
Dissertatio inauguralis botanica sistens dispositionem generum plantarum Jenensium. His taxonomic classification of plants is summarised in his last work, the
Tabula affinitatum regni vegetabilis (1802), which was notable for its diagram depicting the network of affinities within the vegetable kingdom. His
Synopsis vniversalis analytica genervm plantarvm (1793–4) is the source for valid names for
Melanthiaceae and
Primulaceae. ==Zoology==