Crassula tetragena L. subsp. acutifolia (Lam.) Toleken, subsp. nov., det. H.R. Tölken, 01.1973; Herbarium Willdenow in Herbarium Berlin (B): The scientific names of the Willdenow Herbariums specimens in B are mainly left without author citation as these names are the historic ones used in the handwritten diagnosis by C.L. v. Willdenow on the species folder. D.FL. v. Schlechtendal, who sorted the Herbarium according to the Linnean system, brought it to the present state and annotated the mounted specimens with these names. His enumeration, based on these names, is used in the physical arrangement of the Willdenow Herbarium at B. Schlechtendals annotations of personal names in the lower right corner of the sheets represent the person from which Willdenow received the material, which is not necessarily the collector. Only some of the specimens are further annotated. Names of collectors, donators, determiners or exchanging herbarium keepers are cited in the annotations field. Type names are provided as far as possible. To search for material it is recommended to use the "Herbarium Willdenow. Alphabetical Index", ed. P. Hiepko, 1972.