In 1929/1930, "The Book of Flowers" was published for the first time in three volumes. It features 250 illustrations by Rudolf Koch, woodcuts by Fritz Kredel, hand-colored by Emil Wöllner, and flower identifications by Hans Heil, printed by the Mainz Press. In 1933, a selection with 58 illustrations was released as part of the Insel-Bücherei series, which over the years reached a total print run of nearly half a million copies. This volume of the Insel-Bücherei, which had been out of print for a long time, was reissued to commemorate the fiftieth anniversary of Rudolf Koch's death. The flower images—snowdrops and thistles, field delphiniums and cuckoo flower, meadow foam and poppies, bindweed and eyebright, among others—are some of the most beautiful works left to us by Rudolf Koch.