North American flora.

v. 17, pt. 2 (1912)

North American flora.

v. 17, pt. 3 (1915)

North American flora.

v. 21, pt. 1 (1916)

North American flora.

v. 21, pt. 2 (1917)

North American flora.

v. 22, pt. 1 (1905)