Proceedings of the American Philosophical Society held at Philadelphia for promoting useful knowledge - American Philosophical Society. (American Philosophical Society, 1911)

Proceedings of the American Philosophical Society held at Philadelphia for promoting useful knowledge - American Philosophical Society. (American Philosophical Society, 1914)

Proceedings of the American Philosophical Society held at Philadelphia for promoting useful knowledge - American Philosophical Society. (American Philosophical Society, 1922)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1906)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1921)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1930)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1933)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1943)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 2004)

Proceedings of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1907)

Proceedings of the California Academy of Sciences, 4th series - California Academy of Sciences (California Academy of Sciences, 1911)

Proceedings of the California Academy of Sciences, 4th series - California Academy of Sciences (California Academy of Sciences, 1912)

Proceedings of the California Academy of Sciences, 4th series - California Academy of Sciences (California Academy of Sciences, 1907)

Proceedings of the California Academy of Sciences, 4th series - California Academy of Sciences (California Academy of Sciences, 1953)

Proceedings of the California Academy of Sciences, 4th series - California Academy of Sciences (California Academy of Sciences, 2006)

Proceedings of the Florida Academy of Sciences - Florida Academy of Sciences. (Rose Printing Co., etc, 1940)

Proceedings of the Hawaiian Entomological Society - Hawaiian Entomological Society. (Hawaiian Entomological Society, 1910)

Proceedings of the Hawaiian Entomological Society - Hawaiian Entomological Society. (Hawaiian Entomological Society, 1912)

Proceedings of the Linnean Society of London - Linnean Society of London. (Published for the Linnean Society of London by Academic Press [etc.], 1838)

Proceedings of the Linnean Society of London - Linnean Society of London. (Published for the Linnean Society of London by Academic Press [etc.], 1870)

Proceedings of the Linnean Society of London - Linnean Society of London. (Published for the Linnean Society of London by Academic Press [etc.], 1906)

Proceedings of the Linnean Society of London - Linnean Society of London. (Published for the Linnean Society of London by Academic Press [etc.], 1919)

Proceedings of the Linnean Society of New South Wales - Linnean Society of New South Wales. (Linnean Society of New South Wales, 1878)

Proceedings of the Linnean Society of New South Wales - Linnean Society of New South Wales. (Linnean Society of New South Wales, 1879)

Proceedings of the Linnean Society of New South Wales - Linnean Society of New South Wales. (Linnean Society of New South Wales, 1882)

Proceedings of the Linnean Society of New South Wales - Linnean Society of New South Wales. (Linnean Society of New South Wales, 1883)

Proceedings of the Linnean Society of New South Wales - Linnean Society of New South Wales. (Linnean Society of New South Wales, 1906)

Proceedings of the Linnean Society of New South Wales - Linnean Society of New South Wales. (Linnean Society of New South Wales, 1915)

Proceedings of the Linnean Society of New South Wales - Linnean Society of New South Wales. (Linnean Society of New South Wales, 1936)

Proceedings of the Linnean Society of New South Wales - Linnean Society of New South Wales. (Linnean Society of New South Wales, 1989)

Proceedings of the Royal Society of Edinburgh - Royal Society of Edinburgh. (Royal Society of Edinburgh, 1920)

The Proceedings of the Royal Society of Queensland - Royal Society of Queensland. (Royal Society of Queensland], 1884)

Proceedings of the Royal Society of Victoria. New series - Royal Society of Victoria (Melbourne, Vic.) (Stillwell and Co, 1951)

Proceedings of the United States National Museum - Smithsonian Institution (Smithsonian Institution Press, [etc.], 1882)

Proceedings of the United States National Museum - Smithsonian Institution (Smithsonian Institution Press, [etc.], 1901)

Proceedings of the United States National Museum - Smithsonian Institution (Smithsonian Institution Press, [etc.], 1911)

Proceedings of the United States National Museum - Smithsonian Institution (Smithsonian Institution Press, [etc.], 1919)

Proceedings of the United States National Museum - Smithsonian Institution (Smithsonian Institution Press, [etc.], 1923)

Proceedings of the Washington Academy of Sciences - Washington Academy of Sciences (Washington, D.C.) (Washington Academy of Sciences, 1906)

Proceedings of the Zoological Society of London - Zoological Society of London. (Academic Press, [etc.], 1863)

Proceedings of the Zoological Society of London - Zoological Society of London. (Academic Press, [etc.], 1888)

Proceedings of the Zoological Society of London - Zoological Society of London. (Academic Press, [etc.], 1889)

Prodrome d'une histoire des végétaux fossiles - Brongniart, Adolphe, 1801 -1876 (F. G. Levrault, 1828)

Prodrome de la flore belge - Wildeman, E. de (Emile), 1866 -1947 (A. Castaigne, 1898)

Prodrome de la flore corse : comprenant les résultats botaniques de six voyages exécutés en Corse sous les auspices de M. Emile Burnat - Briquet, John, 1870 -1931 (Georg, 1910)

Prodrome de la flore du Grand-Duché de Luxembourg - Koltz, J. P. J. (Jean Pierre Joseph), 1827 -1907 (L. Schamburger, 1873)

Prodromus florae Hispanicae :seu Synopsis methodica omnium plantarum in Hispania, sponte nascentium vel frequentius cultarum quae innotuerunt - Willkomm, Moritz, 1821 -1895 (E. Schweizerbart, 1861)

Prodromus florae hispanicae, seu synopsis methodica omnium plantarum in Hispania - Willkomm, Moritz, 1821 -1895 (E. Schweizerbart, 1861)

Prodromus florae Hispanicae :seu Synopsis methodica omnium plantarum in Hispania, sponte nascentium vel frequentius cultarum quae innotuerunt - Willkomm, Moritz, 1821 -1895 (E. Schweizerbart, 1880)

Prodromus florae Novae Hollandiae et Insulae Van-Diemen, exhibens characteres plantarum - Brown, Robert, 1773 -1858 (Typis R Taylor, veneunt apud J. Johnson, 1810)

Prodromus florae Novae Hollandiae et Insulae Van-Diemen, exhibens characteres plantarum - Brown, Robert, 1773 -1858 (typis R. Taylor et socii, 1810)

Prodromus floræ Novæ Hollandiæ et Insulæ Van-Diemen : exhibens characteres plantarum quas annis 1802-1805 - Brown, Robert, 1773 -1858 (typis R. Taylor et socii, 1810)

Programme du cours d'histoire naturelle médicale professé à la Faculté de médecine de Paris. 3ème partie, Etude spéciale des plantes employées en médecine - Baillon, H. (Henri), 1827 -1895 (F. Savy, 1878)

Pronunciation of plant names - Garden Club of America. (Reproduced and printed by National Process Company], 1922)

Psyche - Cambridge Entomological Club. (Cambridge Entomological Club, 2012)

Pteridologia : a publication of the American Fern Society - American Fern Society. (The Society, 1989)

Pteridologia : a publication of the American Fern Society - American Fern Society. (The Society, 2002)

Pteridologia : a publication of the American Fern Society - American Fern Society. (The Society, 2007)

Pteridologist - British Pteridological Society. (The Society, 2007)

Pteridologist - British Pteridological Society. (The Society, 2012)

Pteridologist - British Pteridological Society. (The Society, 1996)

Pteridologist - British Pteridological Society. (The Society, 2014)

Pteridophyta und Anthophyta - Wettstein, Richard, Ritter von Westersheim, 1863 -1931 (K.K. Hof- und Staatsdruckerei, 1908)

Pteridophyten - Christ, H. (Hermann), 1833 -1933 (Wilhelm Engelmann, 1896)

Ptéridophytes - Tardieu-Blot, Mme., (Laure) 1902 -1998 (1969)

Ptéridophytes : suivis d'une carte des localités du Gabon - Hallé, Nicolas (1964)

Publication. Field Columbian Museum. Botanical series - Field Columbian Museum. (Field Columbian Museum, 1902)

Publication. Field Columbian Museum. Botanical series - Field Columbian Museum. (Field Columbian Museum, 1900)

Publication. Field Museum of Natural History. Botanical series - Field Museum of Natural History. (Field Museum of Natural History, 1930)

Publication. Field Museum of Natural History. Botanical series - Field Museum of Natural History. (Field Museum of Natural History, 1929)

Publication. Field Museum of Natural History. Botanical series - Field Museum of Natural History. (Field Museum of Natural History, 1940)

Publication. Field Museum of Natural History. Botanical series - Field Museum of Natural History. (Field Museum of Natural History, 1931)

Publication. Field Museum of Natural History. Botanical series - Field Museum of Natural History. (Field Museum of Natural History, 1936)

Publication. Field Museum of Natural History. Botanical series - Field Museum of Natural History. (Field Museum of Natural History, 1938)

Publication. Field Museum of Natural History. Botanical series - Field Museum of Natural History. (Field Museum of Natural History, 1939)

Quarterly Journal of Science, Literature and the Arts - Royal Institution of Great Britain. (1829)

The Quarterly journal of the Geological Society of London - Geological Society of America. (1847)

The Quarterly journal of the Geological Society of London - Geological Society of America. (1851)

The Quarterly journal of the Geological Society of London - Geological Society of America. (1882)

The Quarterly journal of the Geological Society of London - Geological Society of America. (1897)

The Quarterly journal of the Geological Society of London - Geological Society of America. (1905)

The Queensland flora - Bailey, Frederick Manson 1827 -1915 (Printed by H. J. Diddams & co, 1902)

The Queensland flora - Bailey, Frederick Manson 1827 -1915 (Printed by H. J. Diddams & co, 1905)

The Queensland Naturalist - Queensland Naturalists' Club. (Queensland Naturalists' Club], 1932)

Rarity, quality, our specialty, hobby - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Everglades Aquatic Nurseries, 1935)

Recherches sur la flore méridionale de Madagascar - Poisson, Henri, 1877 -1963 (A. Challamel, 1912)

Records of the Auckland Institute and Museum - Auckland Institute; Museum. (Auckland Institute and Museum, 1996)

Records of the Botanical Survey of India - Botanical Survey of India. (Office of Supt. of Govt. Print., India, 1893)

Records of the Botanical Survey of India - Botanical Survey of India. (Office of Supt. of Govt. Print., India, 1903)

Records of the Botanical Survey of India - Botanical Survey of India. (Office of Supt. of Govt. Print., India, 1902)

Records of the Botanical Survey of India - Botanical Survey of India. (Office of Supt. of Govt. Print., India, 1904)

Records of the Botanical Survey of India - Botanical Survey of India. (Office of Supt. of Govt. Print., India, 1912)

Records of the geological survey of India (1876)

La región del Caribe Estadounidense : humedales y peces, una conexión vital - Delgado, Patricia (Administración Nacional de los Océanos y la Atmósfera (NOAA), Oficina de Pesquerías de NOAA, División de Conservación de Habitáculo, 2004)

Reise der o¨sterreichischen Fregatte Novara um die Erde in den Jahren 1857, 1858, 1859 unter den Befehlen des Commodore B. von Wu¨llerstorf-Urbair. Erster Band: Sporenpflanzen, Botanischer Theil (Kaiserlich-Kniglichen Hof- und Staatsdruckerei, in Commission bei K. Gerold, 1870)

Reise der österreichischen Fregatte Novara um die Erde in den Jahren 1857, 1858, 1859 unter den Befehlen des Commodore B. von Wüllerstorf-Urbair - Österreichische Akademie der Wissenschaften. (Kaiserlich-Königliche Hof- und Staatsdruckerei; in Commission bei K. Gerold's Sohn, 1870)

Reisen in Britisch-Guiana in den Jahren 1840-1844 : nebst einer Fauna und Flora Guiana's nach Vorlagen von Johannes Müller, Ehrenberg, Erichson, Klotzsch, Troschel, Cabanis und Andern - Ehrenberg, Christian Gottfried, 1795 -1876 (J. J. Weber, 1847)

Reisen in Ost Afrika in 1859-61. Band III : Abteilung 3 Botanik - Decken, Karl Klaus von der, freiherr, 1833 -1865 ([s.n.], 1879)

Reliquiæ Baldwinianæ: selections from the correspondence of the late William Baldwin ... with occasional notes, and a short biographical memoir - Muhlenberg, Henry, 1753 -1815 (Kimber and Sharpless, 1843)

Reliquiae Dewevreanae ou Enumération systématique des plantes récoltées par Alfr. Dewèvre en 1895-96 dans l'Etat Indépendant du Congo - De Wildeman, Emile 1866 -1947 (1901)

Reliquiae Haenkeanae, seu, Descriptiones et icones plantarum :quas in America meridionali et boreali, in insulis Philippinis et Marianis collegit Thaddaeus Haenke - Šternberg, Kašpar, Graf, 1761 -1838 (Apud J.G. Calve, 1830)

Reliquiae Haenkeanae seu Descriptiones et icones plantarum, quas in America meridionali et boreali, in insulis Philippinis et Marianas collegit Thaddaeus Haenke, philosophiae doctor, phytographus regis hispaniae - Presl, K. B. 1794 -1852 (J.G. Calve, 1835)

Repertorium annuum literaturae botanicae periodicae - Bemmelen, J. A. van. (Erven Loosjes, 1873)