Open-air studies in botany : sketches of British wild flowers in their homes - Praeger, R. Lloyd (Robert Lloyd), 1865 -1953 (Griffin, 1897)

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)

Opuscules de botanique - Clos, Dominique, 1821 -1908 (1859)

The Orchid review (Orchid Review ltd.], 1906)

Organographie végétale, ou description raisonnée des organes des plantes. Pour servir de suite et de développement a la Théorie élémentaire de la botanique, et d'introduction a la physiologie végétale et a la description des familles ... - Candolle, Augustin Pyramus de, 1778 -1841 (Chez Deterville, 1827)

Organologisches, systematisches und Arten-Register zu den Tafeln des Handbuch's der botanischen Terminologie - Bischoff, Gottlieb Wilhelm, 1797 -1854 (J.L. Schrag, 1849)

The origin of species - Darwin, Charles, 1809 -1882 (Books, Inc, 1900)

The origin of species - Darwin, Charles, 1809 -1882 (Literary Classics, 1900)

The origin of species - Darwin, Charles, 1809 -1882 (P.F. Collier, 1909)

The origin of species by means of natural selecti : or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (1904)

The origin of species by means of natural selection, or, the preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (John Murray, 1872)

The origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (John Murray, 1880)

The origin of species by means of natural selection; or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (J. Murray, 1886)

The origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (J. Murray, 1888)

The origin of species by means of natural selection, or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (A.L. Burt, 1899)

The origin of species by means of natural selection : or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (Merrill and Baker, 1900)

The origin of species by means of natural selection, or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (A.L. Burt, 1894)

The origin of species by means of natural selection; or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton and Company, 1889)

The origin of species by means of natural selection; or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton and Company, 1909)

The origin of species by means of natural selection, or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton and Company, 1917)

The origin of species by means of natural selection, or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton, 1899)

The origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (J. Murray, 1902)

The origin of species by means of natural selection : or The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (Hurst, 1872)

Origin of species by means of natural selection, or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (P. F. Collier, 1902)

Origin of species by means of natural selection, or the preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (P. F. Collier, 1905)

Origin of species - Darwin, Charles, 1809 -1882 (H.M. Caldwell Co, 1900)

The origin of the species by means of natural selection - Darwin, Charles, 1809 -1882 (J. Murray, 1910)

Florist's journal (How and Parsons, 1840)

Ornithological miscellany - Mintern Bros., (Trübner and Co., Bernard Quaritch, R.H. Porter, 1876)

Ornithologische Monatsschrift - Deutscher Verein zum Schutze der Vogelwelt. (Kommissions-Verlag der Creutschen Verlagsbuchhandlung, 1891)

The Ornithologist and botanist ([J.E. Blain, 1892)

O.S.U. naturalist - Ohio State University. Biological Club. (Biological Club of Ohio State University, 1903)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1887)

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

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

Our farm crops. Being a popular scientific description of the cultivation, chemistry, diseases, remedies, &c., of the various crops cultivated in Great Britain and Ireland - Wilson, John, 1812 -1888 (Blackie and son, 1859)

Our garden flowers; a popular study of their native lands, their life histories, and their structural affiliations - Keeler, Harriet L. (Harriet Louise), 1846 -1921 (C. Scribner's Sons, 1910)

Outdoor life in England - Fisher, Arthur T. (R. Bentley and son, 1896)

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 botany : taken chiefly from Smith's Introduction ... For the use of schools and students - Smith, James Edward, 1759 -1828 (Cummings and Hilliard for the author, 1819)

Outlines of British fungology; containing characters of above a thousand species of Fungi, and a complete list of all that have been described as natives of the British Isles - Berkeley, M. J. (Miles Joseph), 1803 -1889 (L. Reeve, 1860)

Outlines of classification and special morphology of plants - Balfour, Isaac Bayley, 1853 -1922 (Clarendon Press, 1887)

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)

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)

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

Die palaearktischen tortriciden. Eine monographische darstellung mit 24 tafeln in farbendruck, einer stammtafel und mehreren abbildungen im text. Mit einer unterstützung des "Elizabeth-Thompson-science fund" in Boston bearb. von dr. J. Kennel - Kennel, Julius von, 1854 -1939 (E. Schweizerbart, 1921)

Palaeontographica (Theodor Fischer, 1900)

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

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1881)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1884)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1886)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1887)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1892)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1904)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1914)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1916)

Pamphlets on silviculture (1899)

Papers and proceedings of the Royal Society of Tasmania - Royal Society of Tasmania. (The Society, 1877)

Papilio - Edwards, Henry, 1827 -1891 (New York Entomological Club, 1884)

Park and cemetery - Haight, R. J. (Rufus J.) (R.J. Haight, 1898)

Park's floral guide : 1914 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Geo. W. Park, 1914)

Park's illustrated flower book of choice dependable seeds : season of 1929 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Geo. W. Park, 1929)

Part first of a supplement to the Cybele Britannica : to be continued occasionally as a record of progressive knowledge concerning the distribution of plants in Britain - Watson, Hewett Cottrell, 1804 -1881 (Printed for private distribution, 1860)

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)

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

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)

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)

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

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

Peter Parley's cyclopedia of botany : including familiar descriptions of trees, shrubs and plants - Parley, Peter. (Otis, Broaders and Co, 1838)

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)

Petites nouvelles entomologiques (E. Deyrolle, 1869)

P.F. Cürie's Anleitung, die im mittleren und nördlichen Deutschland wildwachsenden und angebauten Pflanzen auf eine leichte und sichere Weise durch eigene Untersuchung zu bestimmen - Cürie, P. F. (C.G. Zobel, 1856)

Pflanzen-Atlas nach dem Linné'schen System - Hoffmann, Carl, 1802 -1883 (Jul. Hoffmann, 1881)

Die pflanzen-mischlinge : ein beitrag zur biologie der gewächse - Focke, Wilhelm Olbers, 1834 -1922 (Gebrüder Borntrager, 1881)

Pflanzen-teratologie systematisch geordnet - Penzig, O. (Ottone), 1856 -1929 (A. Ciminago, 1894)

Die Pflanzen und Raupen Deutschlands : Versuch einer lepidopterologischen Botanik - Wilde, O. (E.S. Mittler, 1860)

Pflanzenbiologische Untersuchungen : nebst algologischen Schluszbemerkungen - Hansgirg, Antonin, 1854 -1917 (Alfred Hölder, 1904)

Die Pflanzendecke Österreich-Ungarns. Auf Grund fremder und eigener Forschungen geschildert - Hayek, August von, 1871 -1928 (F. Deuticke, 1914)

Die Pflanzenfeinde aus der Klasse der Insekten. Ein nach Pflanzenfamilien geordnetes Handbuch sämmtlicher auf den einheimischen Pflanzen bisher beobachteten Insekten zum Gebrauch für Entomologen, Insektensammler, Botaniker, Land- und Forstwirthe und Gartenfreunde - Kaltenbach, J. H. (Johann Heinrich), 1807 -1876 (J. Hoffmann, 1874)