Opera e periodicis collata - Vries, Hugo de, 1848 -1935 (A. Oosthoek, 1918)

Theophrasti Eresii De historia plantarum libri decem, Graece : cum syllabo generum et specierum, glossario, et notis - Theophrastus. (S. Collingwood, 1813)

The orchids in the Ottawa District : floristics, phytogeography, population studies and historical review / Joyce M. Reddoch and Allan H. Reddoch - Ottawa Field-Naturalists' Club (The Ottawa Field-Naturalists' Club, 1997)

Organic evolution as the result of the inheritance of acquired characters according to the laws of organic growth - Eimer, Theodor, 1843 -1898 (Macmillan, 1890)

Organographie der Pflanzen, insbesondere der Archegoniaten und Samenpflanzen - Goebel, K. (Karl), 1855 -1932 (G. Fischer, 1898)

Organographie der Pflanzen, insbesondere der Archegoniaten und Samenpflanzen - Goebel, K. (Karl), 1855 -1932 (G. Fischer, 1913)

Origin and history of all the pharmacopeial vegetable drugs, chemicals and preparations with bibliography... Prepared under the auspices of and pub. by the American drug manufacturers' association, Washington, D.C - Lloyd, John Uri, 1849 -1936 (The Caxton press, 1921)

The origin and history of our garden vegetables, to which is added their dietetic values - Henslow, George, 1835 -1925 (Pub. for the Author by the Royal Horticultural Society, 1912)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1896)

Ornithographia rossica = Ornitologicheskaia fauna Rossii imperii = Die Vogelfauna des russischen Reichs - Pleske, F. D. (Feodor Dmitrievich), 1858 -1932 (Académie impériale des sciences [etc.], 1890)

Ortus sanitatis - Prüss, Johann, 1446 or 1447 -1510 (Johann Prüss)

Die Ostsudeten; eine floristische Skizze - Hruby, Johann. (Landesdurch-forschungs-Komemission, 1914)

O.S.U. naturalist - Ohio State University. Biological Club. (Biological Club of Ohio State University, 1902)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1889)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1892)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1894)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1904)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1906)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1916)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1915)

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

Outlines of medical botany :comprising vegetable anatomy and physiology...and a glossary of terms - Reid, Hugo. (Maclachlan, Stewart & Co, 1896)

Outlines of the natural history of Great Britain and Ireland, containing a systematic arrangement and concise description of all the animals, vegetables and fossiles which have hitherto been discovered in these kingdoms - Berkenhout, John, 1730 -1791 (Printed for P. Elmsly (Successor to Mr. Vaillant), 1770)

Over de bevruchting der bloemen in het kempisch gedeelte van Vlaanderen - MacLeod, Julius, 1857 -1919 (Vuylsteke, 1894)

Overcoming temperature-dependent dormancy of southwestern ponderosa pine seed - Rocky Mountain Forest; Range Experiment Station (Fort Collins, Colo.) (USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, 1981)

Oversigt over det Kongelige Danske videnskabernes selskabs forhandlinger = Bulletin de l'Académie royale des sciences et des lettres de Danemark - Kongelige Danske videnskabernes selskab. (A.F. Høst, 1884)

Oversigt over det Kongelige Danske videnskabernes selskabs forhandlinger = Bulletin de l'Académie royale des sciences et des lettres de Danemark - Kongelige Danske videnskabernes selskab. (A.F. Høst, 1894)

Oversigt over det Kongelige Danske videnskabernes selskabs forhandlinger = Bulletin de l'Académie royale des sciences et des lettres de Danemark - Kongelige Danske videnskabernes selskab. (A.F. Høst, 1896)

Oversigt over det Kongelige Danske videnskabernes selskabs forhandlinger = Bulletin de l'Académie royale des sciences et des lettres de Danemark - Kongelige Danske videnskabernes selskab. (A.F. Høst, 1901)

Oxford gardens, based upon Daubeny's Popular guide to the physick garden of Oxford: with notes on the gardens of the colleges and on the University park - Gunther, R. T. (Robert Theodore), 1869 -1940 (Parker & son; [etc., etc.], 1912)

Oxford gardens. Based upon Daubeny's Popular guide to the physick garden of Oxford : with notes on the gardens of the colleges and on the University Park - Gunther, R. T. (Robert Theodore), 1869 -1940 (Parker, 1912)

Oysters, and all about them : being a complete history of the titular subject, exhaustive on all points of necessary and curious information from the earliest writers to those of the present time, with numerous additions, facts, and notes - Philpots, John Richards. (J. Richardson, 1890)

Pacific science - University of Hawaii. (University Press of Hawaii, 1947)

Pacific science - University of Hawaii. (University Press of Hawaii, 1960)

Une page d'histoire de la medecine : la thérapeutique sous les premiers Césars - Lépine, R. (Raphael), 1840 -1919 (F. Alcan, 1890)

Palaeontographica (Theodor Fischer, 1864)

Palaeontographica (Theodor Fischer, 1875)

Palestine : the physical geography and natural history of the Holy Land - Kitto, John, 1804 -1854 (Charles Knight, 1841)

Palladin's Plant physiology - Hopping, Aleita, 1890 - (P. Blakiston's son, 1926)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1883)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1885)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1888)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1889)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1892)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1895)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1904)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1914)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1916)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1917)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1918)

Pamphlets on forestry in North Dakota and South Dakota (1900)

Pamphlets on silviculture (1899)

Papers and proceedings of the Royal Society of Tasmania - Royal Society of Tasmania. (The Society, 1883)

Papers on Diptera - Meade, Richard Henry 1814 -1899 (Smithsonian Institution, 1881)

Papers on Diptera - Kertész, Kálmán, 1867 -1922 (Smithsonian Institution, 1913)

Papers on Mollusca of Japan - Pilsbry, Henry Augustus, 1862 -1957 (1901)

Papillons d'Europe, peints d'après nature - Devillers, Charles, 1724 -1809 (Chez P.M. Delaguette, imprimeur-libraire, 1785)

Parasitic fungi of Illinois / by T.J. Burrill - Earle, F. S. (Franklin Sumner), 1856 -1929 (J. W. Franks, 1885)

I parassiti vegetali delle piante coltivate od utili - Ferraris, Teodoro. (Sineo & Bo, 1913)

Part I. The living flora of West Virginia - Millspaugh, Charles Frederick, 1854 -1923 (Wheeling news litho. co, 1913)

Parte práctica de botánica del caballero Cárlos Linneo, que comprehende las clases, órdenes, géneros, especies y variedades de las plantas, con sus caracteres genéricos y especificos, sinónimos mas selectos, nombres triviales, lugares donde nacen, y propriedades - Linné, Carl von, 1707 -1778 (En la Imprenta Real, 1784)

Pathological plant anatomy - Küster, E. (Ernst), 1874 -1953 (1913)

Patologia vegetale. Fanerogame parassite, mixomiceti, bacterii, ifomiceti od eumiceti (funghi) - Voglino, Pietro. (Unione tipografico-editrice [Gia ditta Pomba e c], 1905)

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

Pauli Hermanni ... Paradisus batavus, innumeris exoticis curiosis herbis, & rarioribus plantis, magno sumptu & curâ ex variis terrarum orbis regionibus, tam oriente, quam occidente, collectis, acquisitis, illustratus. Ingeniosissima, & dexterrima artificum manu elaboratis iconibus, ad vivum æri incisis. Eruditissimâ suâ, & magnorum in re herbaria versatissimorum virorum, methodicâ descriptione, & catalogo plantarum, nondum præ immatura morte auctoris delineatarum, locupletatus - Hermann, Paul, 1646? -1695 (apud Petrum van der Aa, 1705)

Paxton's Botanical dictionary; comprising the names, history, and culture of all plants known in Britain; with a full explanation of technical terms. New ed. including all the new plants up to the present year - Paxton, Joseph, Sir, 1803 -1865 (Bradbury, Evans, & co, 1868)

Peace-Athabaska weeds : a reconnaissance appraisal - Canada. Department of Agriculture. (Division of Botany, Dept. of Agriculture, 1937)

Pearce seeds, plants and bulbs : offer 45A (1946) - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Rex D. Pearce, 1946)

Pearce seeds, plants, bulbs - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Rex D. Pearce, 1945)

Pearce seeds, plants, bulbs : offer 39A - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Rex D. Pearce, 1943)

Pedanii Dioscoridis anazerbei De materia medica libri quinque : ad fidem cadicum manuscriptorum - Sprengel, Kurt Polycarp Joachim, 1766 -1833 (Cnobloch, C. (Carl), 1778-1834, 1829)

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

Pestmegye és tájéka viránya - Gönczy, Pál, 1817 -1892 (Ráth mór Bizománya, 1864)

Pestmegye és tájéka viránya - Gönczy, Pál, 1817 -1892 (Magyar Királyi Egyetemi Nyomda Sajátja, 1879)

Petite flore de Belgique à l'usage des écoles - Cogniaux, Alfred, 1841 -1916 (Hector Manceaux, 1883)

Petite flore de la Mayenne - Léveillé, H. (Hector), 1863 -1918 (Goupil, 1895)

Petri Andreae Matthioli ... Commentarii secvndo avcti, in libros sex Pedacii Dioscoridis Anazarbei, de medica materia : adiectis quamplurimis plantarum, & animalium imaginibus, quæ in priore editione non habentur, eodem auctore. His accessit eivsdem Apologia adversvs Amathum Lusitanum - Mattioli, Pietro Andrea, 1501 -1577 (in officina Valgrisiani, 1560)