Flora of the northwest coast, including the area west of the summit of the Cascade Mountains, from the forty-ninth parallel south to the Calapooia Mountains on the south border of Lane County, Oregon - Piper, Charles V. (Charles Vancouver), 1867 -1926 (Press of the New Era Printing Company, 1915)

The flora of the Palouse region. Containing descriptions of all the Spermatophytes and Pteridophytes known to grow wild in the area within 35 kilometers of Pullman, Washington - Piper, Charles V. (Charles Vancouver), 1867 -1926 (Washington Agricultural College and School of Science, 1901)

Flora of the Patuxent Research Refuge, Maryland - U.S. Fish; Wildlife Service (U.S. Dept. of the Interior, Fish and Wildlife Service, 1940)

Flora of the Queen Charlotte Islands - Calder, James A. (James Alexander), 1915 -1990 (Queen's Printer], 1968)

The flora of the Raritan formation - Berry, Edward Wilber, 1875 -1945 (MacCrellish & Quigley, printers, 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, 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 the neighboring parts of Nebraska, South Dakota, and British Columbia - Rydberg, Per Axel, 1860 -1931 (The author, 1922)

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)

Flora of the southeastern United States; being descriptions of the seed-plants, ferns and fern-allies growing naturally in North Carolina, South Carolin, Georgia, Florida, Tennessee, Alabama, Mississippi, Arkansas, Louisiana and the Indian territory and in Oklahoma and Texas east of the one-hundredth meridian - Small, John Kunkel, 1869 -1938 (The author, 1903)

Flora of the southeastern Washington and adjacent Idaho - Piper, Charles V. (Charles Vancouver), 1867 -1926 (Press of the New Era Printing Company, 1914)

Flora of the state of Washington - Piper, Charles V. (Charles Vancouver), 1867 -1926 (G.P.O, 1906)

Flora of the state of Washington - Piper, Charles V. (Charles Vancouver), 1867 -1926 (Govt. Print. Off, 1906)

The flora of the town of Southold, Long Island, and Gardiner's Island - Burnham, Stewart H. (Stewart Henry), 1870 -1943 (Torrey Botanical Club, 1914)