On the crustacea and echinodermata of the Pacific shores of North America - Stimpson, William, 1832 -1872 (Boston Society of Natural History, 1857)

The Ontario natural science bulletin - Wellington Field Naturalists' Club. (Wellington Field Naturalists' Club, 1909)

Österreichs Holzpflanzen = : Plantae lignosae Imperii Austriaci : eine auf genaue Berücksichtigung der merkmale der Laubblätter gegründete floristische Bearbeitung aller im Österreichischen Kaiserstaate wild wachsenden oder häufig cultivirten Bäume, Sträucher und Halbsträucher - Pokorny, Alois, 1826 -1886 (K.K. Hof- und Staatsdruckerei, 1864)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1903)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1902)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1907)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1908)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1912)

Outlines of botany for the high school laboratory and classroom (based on Gray's Lessons in botany) - Leavitt, Robert Greenleaf, 1865 -1942 (American Book Co, 1901)

Pamphlets on forest protection (1900)

Pamphlets on forestry in California (1900)

Pamphlets on forestry in Nebraska (1900)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1963)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1994)

Patterson's numbered check-list of North American plants north of Mexico - Patterson, Harry N. (Harry Norton), 1853 -1919 (Patterson, 1892)

Pesticides documentation bulletin - National Agricultural Library (U.S.) (National Agricultural Library, U.S. Dept. of Agriculture, #c 1965-1969, 1965)

Pflanzen-geographie auf physiologischer Grundlage - Schimper, A. F. W. (Andreas Franz Wilhelm), 1856 -1901 (Gustav Fischer, 1908)

Die Pflanzenwelt - Warburg, Otto, 1859 -1938 (Bibliographisches Institut, 1913)

Die Pflanzenwelt Dalmatiens - Adamović, Lujo (Lujo V.), 1869 -1935 (W. Klinkhardt, 1911)

Pharmacal plants and their culture - Schneider, Albert, 1863 -1928 (Richardson, Superintendent of State Printing, 1912)

The Philippine journal of science - Philippines. National Science Development Board. (Bureau of Science, 1909)

Phoradendron on conifers - United States. Forest Service. (U.S. Dept. of Agriculture, Forest Service, 1981)

Phytogeographic survey of North America. A consideration of the phytogeography of the North American continent, including Mexico, Central America and the West Indies, together with the evolution of North American plant distribution - Harshberger, John W. (John William), 1869 -1929 (W. Engelmann, 1911)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 1968)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 1976)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 1980)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 1981)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 1983)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 1986)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 1989)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 1996)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 1997)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 1998)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 2013)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 2015)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 2016)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 2017)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 2018)

Phytoneuron (Guy L. Nesom, 2012)

Phytoneuron (Guy L. Nesom, 2014)

Plant associations of region two : potential plant communities of Wyoming, South Dakota, Nebraska, Colorado, and Kansas - Johnston, Barry C. (USDA Forest Service, Rocky Mountain Region, 1987)

Plant associations of the Crooked River National Grassland - United States. Forest Service. Pacific Northwest Region. (USDA, Forest Service, Pacific Northwest Region, 1983)

Plant diseases in Montana in 1928 - Morris, H. E. (Office of Mycology and Disease Survey, Bureau of Plant Industry, United States Department of Agriculture, 1929)

Plant ecology - McDougall, W. B. (Walter Byron), 1883 - (Lea & Febiger, 1941)