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

Ornamental gardening in Florida - Simpson, Charles Torrey, 1846 -1932 (The author, 1916)

Ornamental trees and plants - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (California Nursery Company, 1908)

Out-of-the-ordinary bulbs for 1958 : 30 years of catering to the bulb collector - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Oakhurst Gardens, 1958)

Out-of-the-ordinary bulbs for 1958 : 31 years of catering to the bulb collector - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Oakhurst Gardens, 1959)

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 - Goebel, K. (Karl), 1855 -1932 (Clarendon Press, 1887)

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

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)

Paléontologie française : description zoologique et géologique de tous les animaux mollusques et rayonnés fossiles de France : comprenant leur application à la reconnaissance des couches - Orbigny, Alcide Dessalines d', 1802 -1857 (Chez l'auteur, 1840)

Papers and proceedings of the Royal Society of Tasmania - Royal Society of Tasmania. (The Society, 1879)

The parks and gardens of Paris, considered in relation to the wants of other cities and of the public and private gardens; being notes on a study of Paris gardens - Robinson, W. (William), 1838 -1935 (Macmillan and co, 1878)

The parks, promenades & gardens of Paris : described and considered in relation to the wants of our own cities and of public and private gardens - Robinson, W. (William), 1838 -1935 (John Murray, 1869)

The parks, promenades, & gardens of Paris, described and considered in relation to the wants of our own cities, and the public and private gardens - Robinson, W. (William), 1838 -1935 (J. Murray, 1869)

Partial stock list of everything pertaining to horticulture for 1905 now in stock at the Universal Horticultural Establishment - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (W.A. Manda, 1905)

Partial stock list of everything pertaining to horticulture for 1907 : now in stock at the Universal Horticultural Establishment - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (W.A. Manda, 1907)

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

Pathologische Pflanzenanatomie. In ihren Grundzügen - Küster, Ernst, 1874 -1953 (G. Fischer, 1916)

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

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)

Paxton's flower garden - Lindley, John, 1799 -1865 (Cassell, Petter, Galpin & Co, 1882)

Paxton's flower garden - Lindley, John, 1799 -1865 (Cassell, Petter, Galpin & Co, 1883)

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 Henderson & Co.'s spring 1899 florists' and market gardeners' wholesale catalogue of plants, flower seeds, bulbs, vegetable seeds, farm seeds, fertilizers, insecticides, tools. etc - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Peter Henderson & Co, 1899)

Pflanzen-geographie auf physiologischer Grundlage - Schimper, A. F. W. (Andreas Franz Wilhelm), 1856 -1901 (Gustav Fischer, 1908)

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

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

Pflanzenphysiologie; ein Handbuch der Lehre vom Stoffwechsel und Kraftwechsel in der Pflanze - Pfeffer, W. (Wilhelm), 1845 -1920 (W. Engelmann, 1897)

Das Pflanzenreich :regni vegetablilis conspectus - Engler, Adolf, 1844 -1930 (W. Engelmann, 1905)