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 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, 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 the neighboring parts of Nebraska, South Dakota, and British Columbia - Rydberg, Per Axel, 1860 -1931 (The author, 1922)

Flora of the Santa Monica Mountains, California - Thompson, Henry J. (University of California, 1986)

A flora of the Santa Rosa plateau : an annotated list of the vascular plants and the plant communities of the Santa Rosa plateau, Santa Ana Mountains - Thorne, Robert F. (s.n, 1985)

Flora of the southeastern United States; being descriptions of the seed-plants, ferns and fern-allies growing naturally in North Carolina, South Carolina, Georgia, Florida, Tennessee, Alabama, Mississippi, Arkansas, Louisiana, and in Oklahoma and Texas east of the one hundredth meridian - Small, John Kunkel, 1869 -1938 (The author, 1913)