- An Illustrated Flora of the Northern United States and Canada, Vol. 3
- An Illustrated Flora of the Northern United States and Canada, Vol. 2
- An Illustrated Flora of the Northern United States and Canada, Vol. 1
- The Cactaceae: Descriptions and Illustrations of Plants of the Cactus Family (Volume 3 and 4 Bound in One Volume)
- The Cactaceae, Vol. 1