Wild Flowers Worth Knowing is a book published in 1917 (and republished in 1922) as a result of an adaptation by Asa Don Dickinson of Neltje Blanchan's earlier work Nature's Garden (1900).
It covers mostly North American species, with a sprinkling of cosmopolitans, and includes a preface by Blanchan (who died in 1918).
[1] It contains over 40 color illustrations accompanying the text, which is arranged by plant family under the classification system of Gray's New Manual of Botany as revised by Robinson and Fernald.
[3] Wild Flowers Worth Knowing was briefly reviewed by The Outlook along with a few other books in the Little Nature Library series as, "well printed, well illustrated, and admirably adapted for home and school use.
The review goes on to comment that beginners may have difficulty in using Wild Flowers as a practical field guide because it assumes the user can identify the specimen to a plant family.