The book "Families of Flowering Plants" was written by Hutchinson. Hutchinson's work is significant in the classification and identification of plant families. The book is a comprehensive work on the families of flowering plants and is widely recognized in the field of plant taxonomy.
- Bentham and Hooker also made significant contributions to plant classification, but their work, "Genera Plantarum," is more focused on the description of plant genera.
- Engler and Prantl are known for their "Die Natürlichen Pflanzenfamilien," another important work on plant families, but it is not the book being referenced in this question.
- Linnaeus is credited with developing the binomial nomenclature system but did not write the "Families of Flowering Plants."
Thus, the correct answer is (3) Hutchinson.