Bulletin of the Torrey Botanical Club - Torrey Botanical Club. (Torrey Botanical Club, 1913)

Contributions from the New York Botanical Garden - New York Botanical Garden (The Garden, 1912)

The flora of Boulder, Colorado, and vicinity - Daniels, Francis Potter, 1869 -1947 (The University of Missouri, 1911)

Flora of the Rocky Mountains and adjacent plains, Colorado, Utah, Wyoming, Idaho, Montana, Saskatchewan, Alberta, and neighboring parts of Nebraska, South Dakota, North Dakota, and British Columbia - Rydberg, Per Axel, 1860 -1931 (The author, 1922)

Flora of the Rocky Mountains and adjacent plains, Colorado, Utah, Wyoming, Idaho, Montana, Saskatchewan, Alberta, and neighboring parts of Nebraska, South Dakota, North Dakota, and British Columbia - Rydberg, Per Axel, 1860 -1931 (The author, 1922)

Flora of the Rocky Mountains and adjacent plains : Colorado, Utah, Wyoming, Idaho, Montana, Saskatchewan, Alberta, and neighboring parts of Nebraska, South Dakota, North Dakota, and British Columbia - Rydberg, Per Axel, 1860 -1931 (Rydberg, 1917)

Flora of the Rocky Mountains and adjacent plains, Colorado, Utah, Wyoming, Idaho, Montana, Saskatchewan, Alberta, and neighboring parts of Nebraska, South Dakota, and British Columbia - Rydberg, Per Axel, 1860 -1931 (The author, 1917)

Flora of the Rocky Mountains and adjacent plains, Colorado, Utah, Wyoming, Idaho, Montana, Saskatchewan, Alberta, and the neighboring parts of Nebraska, South Dakota, and British Columbia - Rydberg, Per Axel, 1860 -1931 (The author, 1922)

Index Kewensis plantarum phanerogamarum. nomina et synonyma omnium generum et specierum ab initio anni MDCCCCVI usque ad finem anni MDCCCCX complectens Supplementum quartum - Royal Botanic Gardens, Kew. (e prelo Clarendoniano, 1913)

New manual of botany of the central Rocky Mountains, vascular plants - Coulter, John Merle, 1851 -1928 (American Book Co, 1909)

New manual of botany of the central Rocky mountains (vascular plants) - Coulter, John Merle, 1851 -1928 (American book company, 1909)

New manual of botany of the central Rocky mountains (vascular plants) - Coulter, John Merle, 1851 -1928 (American Book Company, 1909)

Das Pflanzenreich :regni vegetablilis conspectus - Engler, Adolf, 1844 -1930 (W. Engelmann, 1907)

Studies on Rocky Mountain flora - Rydberg, Per Axel, 1860 -1931 (New York Botanical Garden, 1913)

The University of Missouri studies Science series - University of Missouri. (The University, 1905)