Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1993)

Oecology of plants : an introduction to the study of plant-communities - Vahl, M. (Martin), 1749 -1804 (Clarendon Press, 1909)

Oecology of plants : an introduction to the study of plant-communities - Warming, Eugenius, 1841 -1924 (Clarendon Press, 1909)

Oecology of plants; an introduction to the study of plant-communities - Balfour, Isaac Bayley, 1853 -1922 (Clarendon Press, 1909)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1862)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1883)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1891)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1895)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1896)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1897)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1913)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1915)

Oesterreichisches botanisches Wochenblatt ([L.W. Seidel], 1851)

Oesterreichisches botanisches Wochenblatt ([L.W. Seidel], 1854)

Official guide to the museums of economic botany. No. 1, Dicotyledons - Royal Botanic Gardens, Kew. (Printed for H.M. Stationery Off., by Darling, 1907)

Oil spill sensitivity of the western Indian Ocean islands: coastal data from the Comoros Islands, Madagascar, Mauritius, Reunion and the Seychelles - Green, Edmund P. (Edmund Peter) 1965 - (WCMC, 1998)

Les Ombellifères : contributions pluridisciplinaires à la systématique : actes du 2e Symposium International sur les Ombellifères, Centre Universitaire de Perpignan, 18-21 mai 1977 - Cauwet-Marc, A.-M. (Anne-Marie) (Missouri Botanical Garden, 1977)

Opmerkingen over eene Buitenzorgsche Kritiek op mijne Exkursionsflora von Java : verweerschrift, op last van den Hoofdinspecteur-Chef van den Dienst van het Boschwezen van Nederlandsch-Indië - Koorders, Sijfert Hendrik, 1863 -1919 (G. Kolff, 1914)

Oréades - Instituto de Ciências Biológicas da UFMG. Departamento de Botânica. (Departamento de Botânica, U.F.M.G, 1970)

Oréades - Instituto de Ciências Biológicas da UFMG. Departamento de Botânica. (Departamento de Botânica, U.F.M.G, 1972)

Oréades - Instituto de Ciências Biológicas da UFMG. Departamento de Botânica. (Departamento de Botânica, U.F.M.G)

Oréades - Instituto de Ciências Biológicas da UFMG. Departamento de Botânica. (Departamento de Botânica, U.F.M.G, 1981)

Organography of plants, especially of the archegoniatae and spermaphyta - Goebel, K. (Karl), 1855 -1932 (Clar. Press, 1900)

The ornamental trees of Hawaii - Rock, Joseph F. (Joseph Francis), 1884 -1962 (1917)

Ornithological science - Nihon Chogakkai (Ornithological Society of Japan, 2002)

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)

Our South African flora = Ons Suid-Afrikaanse plantegroei - Compton, R. H. (Cape Times, 1900)

An outline of plant geography (The Macmillan company, 1926)

Outline of the flora of Trinidad - Crüger, Herman, 1818 -1864 (Peter and Galpin, 1858)

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

Outlines of classification and special morphology of plants - Goebel, K. (Karl), 1855 -1932 (Clarendon Press, 1887)

Outlines of creation - Noyce, Elisha. (Ward & Lock, 1858)

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)

Pacific science - University of Hawaii. (University Press of Hawaii, 1958)

Pacific science - University of Hawaii. (University Press of Hawaii, 1967)

Pacific science - University of Hawaii. (University Press of Hawaii, 1968)

Palaeontographica (Theodor Fischer, 1846)

Palaeontographica Americana - Paleontological Research Institution (Ithaca, N.Y.) (Paleontological Research Institution, 1994)

Palaeontology - Palaeontological Association (Palaeontological Association, 1966)

Paleobotany and biogeography : a festschrift for Alan Graham in his 80th year - Raven, Peter H (Missouri Botanical Garden, 2014)

[Pamphlets on agriculture in Guam] (s.n, 1905)

Pamphlets on forestry in Texas (1900)

Pamphlets on silviculture (1899)

Pamphlets on the lumber industry (1900)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1995)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 2001)

Perú: Cordillera Escalera-Loreto - Stotz, Douglas F. (Douglas Forrester), 1956 - (The Field Museum, Science and Education, 2014)

Peru : Ere-Campuya-Algodón - Field Museum of Natural History. (The Field Museum, Science and Education, 2013)

Peru : Maijuna - Alverson, William Surprison (Field Museum, Environment, Culture and Conservation, 2010)

Perú : Cerros de Kampankis - Stotz, Douglas F. (Douglas Forrester), 1956 - (The Field Museum, Environment, Culture, and Conservation, 2012)

Perú, Medio Putumayo-Algodón - Stotz, Douglas F. (Douglas Forrester), 1956 - (Field Museum of Natural History, 2016)

Perú : Nanay-Mazán-Arabela - Alverson, William Surprison (Field Museum, Environmental and Conservation Programs, 2007)

Perú : Tapiche-Blanco - Field Museum of Natural History. (The Field Museum, 2015)

Perú : Yaguas-Cotuhé - Field Museum of Natural History. (Field Museum, Environment, Culture, and Conservation, 2011)

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

Peter S. Ashton Sarawak fieldwork papers - Ashton, Peter S. (Peter Shaw), 1934 - (1963)