| title | ISBN-13 (ISBN-10) | year of publica- tion | other author(s) |
|---|---|---|---|
| Flower Finder: A Guide to the Identification of Spring Wild Flowers and Flower Families East of the Rockies and North of the Smokies, Exclusive of Trees and Shrubs | 978-0-912550-00-8 (0-912550-00-7) | 1955 | |
| Tree Finder: A Manual for the Identification of Trees by Their Leaves | 978-0-912550-01-5 (0-912550-01-5) | 1963 | |
| Winter Tree Finder: A Manual for Identifying Deciduous Trees in Winter | 978-0-912550-03-9 (0-912550-03-1) | 1970 | Tom Watts |
M. T. · M W · M. Watts · May Theilgaard Watts · May-W · T W · T. Watts