In the legacy of Sándor Jávorka deposited in the Hungarian Natural History Museum there is a 12-page typescript entitled “An identification key for Hungarian botanists portrayed in Album Kleinianum (Budapest, 25 September 1912)”. It provides accurate descriptions of 50 botanists in the form of an identification key, which was compiled by Zoltán Szabó, a well-known botanist at that time. The most important features of each person are presented in a humorous, basically ironic, funny and witty way. The Identification key was prepared for the session no. 178 of the Botanical Section of the Royal Hungarian Natural Science Society, where another botanist, Gyula Klein was congratulated on the 40^th anniversary of his teaching profession as well as the 20^th anniversary of his membership in the society. Almost all prominent botanists attended the meeting. This paper presents the Identification key, supplied with annotations and photographs.