Macrochemical colour reactions of benzidine were studied mainly with the species of genera Agaricus, Amanita, Lactarius, Russula, and Tricholoma. With the genus Lactarius, differences were found between the reactions of the milk and the context. Oxidation enzymes, which give a blue-green, blue, or black reaction, were detected in many species of the genera Agaricus, Lactarius, and Russula, whereas with Amanita and most species of Tricholoma they were absent. In the case of the genus Russula, only species with a burning taste give a yellow or ochre reaction. The reactions of benzidine are suitable as complementary characteristics for the determination of some mutually similar species.
Micka K., Klán J. (1980): Chemical spot tests of macromycetes with benzidine. – Česká Mykologie 34(2): 74–81.