Plants

Flower Guide: Wild Flowers East of the Rockies (Revised and with New Illustrations)

Spring in a Shropshire Abbey

Young Folks' Nature Field Book

Language of Flowers

Street Trees

History of Botany (1530–1860)

Fruits of the Hawaiian Islands

Ferns of Hawaii National Park

Fossil Forests of the Yellowstone National Park

The Study of Plant Life

The Botanical Lore of the California Indians with Side Lights on Historical Incidents in California

Trees of the Forest: Their Beauty and Use

The Man Who Climbs Trees

The botanist's repository for new and rare plants; vols 1 & 2