Nuova flora analitica d'Italia, contenente la descrizione delle piante vascolari indigene inselvatichite e largamente coltivate in Italia - Fiori, Adriano 1865 -1950 (Tipografia di M. Ricci, 1923)

Nuova flora analitica d'Italia, contenente la descrizione delle piante vascolari indigene inselvatichite e largamente coltivate in Italia - Fiori, Adriano 1865 -1950 (Tipografia di M. Ricci, 1925)

Nuovi annali delle scienze naturali (1854)

Nya botaniska notiser ([A. Bonniers Förlag], 1853)

Nya botaniska notiser ([A. Bonniers Förlag], 1854)

Nyt magazin for naturvidenskaberne - Physiographiske forening i Christiania. (Johan Dahl, 1911)

Oakes Ames Orchid Herbarium correspondence files - Ames, Oakes, 1874 -1950 (1921)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1858)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1873)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1874)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1878)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1883)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1885)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1891)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1892)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1893)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1894)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1896)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1898)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1902)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1904)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1911)

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

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1850)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1854)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1880)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1883)

On molecular and microscopic science - Somerville, Mary Fairfax, 1780 -1872 (J. Murray, 1869)

On molecular and microscopic science - Somerville, Mary, 1780 -1872 (J. Murray, 1869)

Onze flora. Beschrijving van de familiën, voornamste geslachten en soorten der in Nederland in het wild groeiende, verwilderde, verbouwde en aangeplante gewassen, alsmede van eenige fraaie en nuttige midden-europeesche planten - Hoffmann, Carl, 1802 -1883 (W.J. Thieme, 1900)

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

The Orchadian - Australasian Native Orchid Society (The Society, 1970)

The Orchadian - Australasian Native Orchid Society (The Society, 1976)

The Orchadian - Australasian Native Orchid Society (The Society, 1977)

The Orchadian - Australasian Native Orchid Society (The Society, 1963)

The Orchadian - Australasian Native Orchid Society (The Society, 1980)

The Orchadian - Australasian Native Orchid Society (The Society, 1978)

The Orchadian - Australasian Native Orchid Society (The Society, 1984)

The Orchadian - Australasian Native Orchid Society (The Society, 1985)

The Orchadian - Australasian Native Orchid Society (The Society, 1987)

The Orchadian - Australasian Native Orchid Society (The Society, 1989)

The Orchadian - Australasian Native Orchid Society (The Society, 1990)

The Orchadian - Australasian Native Orchid Society (The Society, 1991)

The Orchadian - Australasian Native Orchid Society (The Society, 1992)

The Orchadian - Australasian Native Orchid Society (The Society, 1993)

The Orchadian - Australasian Native Orchid Society (The Society, 1995)

The Orchadian - Australasian Native Orchid Society (The Society, 1999)

The Orchadian - Australasian Native Orchid Society (The Society, 2000)

The Orchadian - Australasian Native Orchid Society (The Society, 2004)

The Orchadian - Australasian Native Orchid Society (The Society, 2007)

The Orchadian - Australasian Native Orchid Society (The Society, 2008)

The Orchid review (Orchid Review ltd.], 1910)

The Orchid review (Orchid Review ltd.], 1917)

The Orchid review (Orchid Review ltd.], 1920)

The Orchid world. A monthly illustrated journal entirely devoted to orchidology - Wilson, Gurney, 1878 - (Alabaster, Passmore & Sons, ltd., printers], 1915)

Orchidaceae: illustrations and studies of the family Orchidaceae - Ames, Oakes, 1874 -1950 (Houghton, Mifflin, 1905)

Orchidaceae: illustrations and studies of the family Orchidaceae - Ames, Oakes, 1874 -1950 (Houghton, Mifflin, 1908)

Orchidaceae: illustrations and studies of the family Orchidaceae - Ames, Oakes, 1874 -1950 (Houghton, Mifflin, 1915)

Orchidaceae: illustrations and studies of the family Orchidaceae - Ames, Oakes, 1874 -1950 (Houghton, Mifflin, 1920)

Orchidaceae: illustrations and studies of the family Orchidaceae - Ames, Oakes, 1874 -1950 (Houghton, Mifflin, 1922)

Orchidaceele din România - Pantu, Zacharia C., 1866 -1934 (Librariile Socec & co. [etc.], 1915)

Orchidacées - Hallé, Nicolas (1977)

Les orchidées, histoire iconographique, organographie, classification, géographie, collections, commerce, emploi, culture, avec une revue descriptive des espèces cultivées en Europe; ouvrage orné de 244 vignettes et de 50 chromolithographics - Puydt, Émile de, 1810 -1891 (J. Rothschild, 1880)

Les orchidées : manuel de l'amateur - Bois, D. (Désiré), 1856 -1946 (J.-B. Baillière et fils, 1893)

Le orchidee - Pucci, Angiolo, 1851 - (U. Hoepli, 1905)

Die Orchideen :ihre Beschreibung, Kultur und Zu¨chtung. Handbuch fu¨r Orchideenliebhaber, Zu¨chter und Botaniker - Schlechter, Rudolf, 1872 -1925 (P. Parey, 1915)

Die Orchideen von Ambon - Smith, J. J. (Johannes Jacobus), 1867 -1947 (Landsdrukkerij, 1905)

Die orchideen von Java - Smith, J. J. (Johannes Jacobus), 1867 -1947 (E. J. Brill, 1905)

Les orchidées exotiques et leur culture en Europe - Cogniaux, Alfred, 1841 -1916 (l'Auteur, 1894)

Orchidophile; journal des amateurs d'orchideés - Godefroy-Lebeuf, A. (Alexandre), 1844 -1903 (1885)

Orchidophile; journal des amateurs d'orchideés - Godefroy-Lebeuf, A. (Alexandre), 1844 -1903 (1886)

Orchidophile; journal des amateurs d'orchideés - Godefroy-Lebeuf, A. (Alexandre), 1844 -1903 (1887)

Orchidophile; journal des amateurs d'orchideés - Godefroy-Lebeuf, A. (Alexandre), 1844 -1903 (1891)

Orchids; being the report on the Orchid Conference held at South Kensington (Macmillan & Co, 1886)

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)

Orchids of Lakeland : a field guide to Lakeland Provincial Park, Provincial Recreation Area and surrounding region - Alberta. Alberta Environmental Protection. (Alberta Environmental Protection, 1998)

The orchids of New England; a popular monograph - Baldwin, Henry, 1846 -1911 (J. Wiley, 1884)