The principles of plant-teratology - Worsdell, Wilson Crosfield (The Ray Society, 1915)

Principles of the anatomy and physiology of the vegetable cell - Mohl, Hugo von, 1805 -1872 (John Van Voorst, 1852)

Proceedings and transactions of the Natural History Society of Glasgow - Natural History Society of Glasgow. (The Society, 1889)

Proceedings and transactions of the South London Entomological & Natural History Society - South London Entomological; Natural History Society (The Society, 1959)

Proceedings : National Wilderness Research Conference, current research, Fort Collins, CO, July 23-26, 1985 - Intermountain Research Station (Ogden, Utah) (Intermountain Research Station, 1986)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1863)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1893)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1913)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1841)

Proceedings of the American Academy of Arts and Sciences - American Academy of Arts; Sciences. (Metcalf and Co, 1857)

Proceedings of the American Academy of Arts and Sciences - American Academy of Arts; Sciences. (Metcalf and Co, 1875)

Proceedings of the American Academy of Arts and Sciences - American Academy of Arts; Sciences. (Metcalf and Co, 1878)

Proceedings of the American Academy of Arts and Sciences - American Academy of Arts; Sciences. (Metcalf and Co, 1902)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1892)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1935)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1990)

Proceedings of the Bristol Naturalists' Society - Bristol Naturalists' Society (Bristol, England) (Bristol Naturalists' Society, 1862)

Proceedings of the Bristol Naturalists' Society - Bristol Naturalists' Society (Bristol, England) (Bristol Naturalists' Society, 1964)

Proceedings of the Cotteswold Naturalists' Field Club - Cotteswold Naturalists' Field Club. (1910)

Proceedings of the Dublin University Zoological and Botanical Association - Dublin University. Zoological; Botanical Association.

Proceedings of the Folkestone Natural History & Microscopical Society - Folkestone Natural History & Microscopical Society. (1868)

Proceedings of the Indiana Academy of Science - Indiana Academy of Science. ([s.n.], 1920)

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, 1912)

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Proceedings of the Literary and Philosophical Society of Liverpool - Literary; Philosophical Society of Liverpool. (1845)

Proceedings of the National Science Club, Washington, D.C - National Science Club, Washington, D.C. (Judd & Detweiler, Printers, 1897)

Proceedings of the Natural history society of Dublin for the session ... - Natural History Society of Dublin. (Printed for the Society, 1878)

Proceedings of the Natural History Society of Glasgow - Natural History Society of Glasgow. (Natural History Society of Glasgow, 1858)

Proceedings of the Natural History Society of Glasgow - Natural History Society of Glasgow. (Natural History Society of Glasgow, 1851)

Proceedings of the Perthshire Society of Natural Science - Perthshire Society of Natural Science. (1880)

Proceedings of the Royal Irish Academy - Royal Irish Academy. (Royal Irish Academy, 1863)

Proceedings of the Royal Irish Academy - Royal Irish Academy. (Royal Irish Academy, 1913)

The Proceedings of the Royal Society of Queensland - Royal Society of Queensland. (Royal Society of Queensland], 1889)

Proceedings of the Royal Society of Victoria. New series - Royal Society of Victoria (Melbourne, Vic.) (Stillwell and Co, 1961)

Proceedings of the Royal Society of Victoria. New series - Royal Society of Victoria (Melbourne, Vic.) (Stillwell and Co, 2004)

Proceedings of the Washington Academy of Sciences - Washington Academy of Sciences (Washington, D.C.) (Washington Academy of Sciences, 1902)

Prodrom der Waldstätter Gefässpflanzen - Rhiner, Joseph, 1830? -1897 (J. Bürgler, 1870)

Prodrome de la flore Belge - De Wildeman, Emile 1866 -1947 (Alfred Castaigne, 1899)

Prodrome de la flore Belge - De Wildeman, Emile 1866 -1947 (Alfred Castaigne, 1898)

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

Prodrome de la flore bryologique de Madagascar, des Mascareignes et des Comores - Renauld, Ferdinand, 1837 -1910 (Impr. de Monaco, 1897)

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

Prodromus florae Batavae - Nederlandsche Botanische Vereeniging, Leyden. (F.E. MacDonald, 1901)

Prodromus florae Batavae - Nederlandsche Botanische Vereeniging, Leyden. (F.E. MacDonald, 1898)

Prodromus florae Batavae - Dozy, F. (Frans), 1807 -1856 (Sumptibus Societatis, apud J. Hazenberg, 1850)

Prodromus florae stargardiensis : continens plantas in Ducatu Megapolitano-Stargardiensi S. Strelitzensi sponte provenientes - Schultz, Karl Friedrich, 1765 -1837 (sumtibus C. F. E. Spaethen, 1806)

Prof. dr. Thomé's Flora von Deutschland, Österreich und der Schweiz, in wort und bild, für schule und haus ... mit ... - Migula, W. (Walter), 1863 -1938 (1904)

Prof. dr. Thomé's Flora von Deutschland, Österreich und der Schweiz, in wort und bild, für schule und haus ... mit ... - Migula, W. (Walter), 1863 -1938 (1913)

Publication. Field Columbian Museum Botanical series - Field Columbian Museum. (Field Columbian Museum, 1896)

Publication. Field Museum of Natural History Botanical series - Field Museum of Natural History. (Field Museum of Natural History, 1927)

Publication. Field Museum of Natural History Botanical series - Field Museum of Natural History. (Field Museum of Natural History, 1923)

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

Publications in botany - National Museum of Natural Sciences (Canada) (The Museum, 1975)

Publications in botany - National Museum of Natural Sciences (Canada) (The Museum, 1980)

Publications in botany - National Museum of Natural Sciences (Canada) (The Museum, 1982)

Pugillus plantarum imprimis Hispanicarum, quas in itinere 1851-52 - Lange, Joh., 1818 -1898 (B. Luno, 1860)

Quarterly journal of microscopical science (J. and A. Churchill [etc.], 1870)

Quarterly journal of microscopical science (J. and A. Churchill [etc.], 1878)

The Quarterly journal of the Geological Society of London - Geological Society of America. (1912)

Rambles in search of flowerless plants - Plues, Margaret (Journal of horticulture & cottage gardener office; [etc., etc.], 1864)

Rare bryophytes of Oregon - United States. Bureau of Land Management. (U.S. Department of the Interior, Bureau of Land Management, Salem District, 2016)

Reading Naturalist. Reading - Reading Natural History Society.

A record of plants collected in Southern Rhodesia; arramged on Engler's system - Eyles, Fred (1916)

A record of the fungi named by J.B. Ellis - United States. Bureau of Plant Industry, Soils,; Agricultural Engineering. (Division of Mycology and Disease Survey, Bureau of Plant Industry, Soils, and Agricultural Engineering, Agricultural Research Administration, U.S. Dept. of Agriculture, 1952)

Records of general science

Recueil de l'Institut botanique (Université de Bruxelles) - Institut botanique Léo Errera. (Henri Lamertin, 1902)

Reduction of all the genera of plants contained in the Catalogus plantarum Americæ septentrionalis, of the late Dr. Muhlenberg, to the natural families of Mr. de Jussieu's system : For the use of the gentlemen who attended the course of elementary and philosophical botany in Philadelphia, in 1815 - Correia da Serra, José Francisco, 1750 -1823 (Published by Solomon W. Conrad, no. 87, Market Street, 1815)

Regni vegetabilis systema naturale, sive Ordines, genera et species plantarum secundum methodi naturalis normas digestarum et descriptarum - Candolle, Augustin Pyramus de, 1778 -1841 (sumptibus sociorum Treuttel et Würtz, 1818)

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 Amur-Land und auf der Insel Sachalin : im Auftrage der Kaiserlich-Russischen Geographischen Gesellschaft ausgefuehrt - Schmidt, Friedrich, 1832 -1908 (Commissionaires de l'Académie impériale des sciences, 1868)

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

Report - British Columbia Provincial Museum. (Printed by W.H. Cullin, 1928)

Report - British Columbia Provincial Museum. (Printed by W.H. Cullin, 1917)

Report - British Columbia Provincial Museum. (Printed by W.H. Cullin, 1926)

Report & transactions - Birmingham Natural History; Microscopical Society (Birmingham, England) (Herald Press)

Report / Botanical Society and Exchange Club of the British Isles - Botanical Society; Exchange Club of the British Isles. (1923)

Report for the year ... - Moss Exchange Club, (Moss Exchange Club, 1907)

Report for the year ... - Moss Exchange Club. Section II, (Moss Exchange Club, 1913)

Report for the year - British Columbia Provincial Museum - British Columbia Provincial Museum. (Printed by A. Sutton [etc.], for the Queen, 1917)

Report of the botanical exploration of southwestern Virginia during the season of 1892 - Small, John Kunkel, 1869 -1938 (1893)

Report of the Botanist - Peck, Charles H. (Charles Horton), 1833 -1917 (University of the State of New York, Office of the Regents, 1868)

Report of the Botanist - New York (State). State Botanist. (James B. Lyon, State Printer, 1867)

Report of the Canadian Arctic Expedition 1913-18 (F. A. Acland, Printer to the King, 1913)

Report of the Folkestone Natural History Society - Folkestone Natural History Society. (1871)

Report of the geological exploration of the fortieth parallel - Eaton, Daniel Cady, 1834 -1895 (G.P.O, 1871)

Report of the Geological Survey of Ohio - Geological Survey of Ohio. (Nevins & Myers, state printers, 1893)