Rapid inventories, biological and social - Field Museum of Natural History. (Field Museum, 2008)

Rare and endangered plants of Puerto Rico : a committee report - United States. Soil Conservation Service. (U.S. Dept. of Agriculture, Soil Conservation Service in cooperation with the Department of Natural Resources, Commonwealth of Puerto Rico, 1975)

Rare and endemic trees of Puerto Rico and the Virgin Islands - United States. Forest Service. (U.S. Dept. of Agriculture, Forest Service, 1980)

Rare and Threatened Plants of Cuba: ex-situ conservation in Botanic gardens (1989)

The Reading Nursery - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Reading Nursery, 1898)

Records of the Auckland Institute and Museum - Auckland Institute; Museum. (Auckland Institute and Museum, 1942)

Records of the Auckland Institute and Museum - Auckland Institute; Museum. (Auckland Institute and Museum, 1948)

Records of the Auckland Institute and Museum - Auckland Institute; Museum. (Auckland Institute and Museum, 1962)

Records of the Auckland Institute and Museum - Auckland Institute; Museum. (Auckland Institute and Museum, 1970)

Records of the Auckland Institute and Museum - Auckland Institute; Museum. (Auckland Institute and Museum, 1994)

Records of the Botanical Survey of India - Botanical Survey of India. (Office of Supt. of Govt. Print., India, 1893)

Records of the Botanical Survey of India - Botanical Survey of India. (Office of Supt. of Govt. Print., India, 1903)

Records of the Botanical Survey of India - Botanical Survey of India. (Office of Supt. of Govt. Print., India, 1902)

Records of the Botanical Survey of India - Botanical Survey of India. (Office of Supt. of Govt. Print., India, 1904)

Records of the Botanical Survey of India - Botanical Survey of India. (Office of Supt. of Govt. Print., India, 1919)

Records of the Botanical Survey of India - Botanical Survey of India. (Office of Supt. of Govt. Print., India, 1953)

Records of the Botanical Survey of India - Botanical Survey of India. (Office of Supt. of Govt. Print., India, 1921)

Records of the Western Australian Museum - Western Australian Museum (Western Australian Museum, 1985)

Records of the Western Australian Museum - Western Australian Museum (Western Australian Museum, 1995)

Records of the Western Australian Museum - Western Australian Museum (Western Australian Museum, 2010)

Records of the Western Australian Museum - Western Australian Museum (Western Australian Museum, 2015)

Recueil des travaux botaniques néerlandais - Koninklijke Nederlandse Botanische Vereniging. (Société botanique néerlandaise, 1907)

Recueil des travaux botaniques néerlandais - Koninklijke Nederlandse Botanische Vereniging. (Société botanique néerlandaise, 1904)

Regiones terrestres prioritarias de México - Aguilar Zúñiga, Claudia (Comisión Nacional para el Conocimiento y Uso de la Biodiversidad (CONABIO), 2000)

Reise in Ostafrika in den Jahren 1903-1905 : mit Mitteln der Hermann und Elise geb. Heckmann Wentzel-Stiftung : Wissenschaftliche Ergebnisse - Voeltzkow, Alfred, 1860 -1946 (E. Schweizerbartsche Verlagsbuchhandlung, 1917)

Reisen in Britisch-Guiana in den Jahren 1840-1844 : nebst einer Fauna und Flora Guiana's nach Vorlagen von Johannes Müller, Ehrenberg, Erichson, Klotzsch, Troschel, Cabanis und Andern - Ehrenberg, Christian Gottfried, 1795 -1876 (J. J. Weber, 1848)

Reisen in Britisch-Guiana in den Jahren 1840-1844 : nebst einer Fauna und Flora Guiana's nach Vorlagen von Johannes Müller, Ehrenberg, Erichson, Klotzsch, Troschel, Cabanis und Andern - Ehrenberg, Christian Gottfried, 1795 -1876 (J. J. Weber, 1847)

Reisen in Süd-Arabien, Mahra-land und Hadramt - Hirsch, Leo. (E.J. Brill, 1897)

Reistochten naar de Geelvinkbaai op Nieuw-Guinea in de jaren 1869 en 1870 - Koninklijk Instituut voor Taal-, Land- en Volkenkunde (Netherlands) (Nijhoff, 1875)

Reliquiae Dewevreanae ou Enumération systématique des plantes récoltées par Alfr. Dewèvre en 1895-96 dans l'Etat Indépendant du Congo - De Wildeman, Emile 1866 -1947 (1901)

Répertoire des noms génériques mentionnés dans l'Index kewensis et ses quinze premiers suppléments = Guide to the generic names appearing in the Index Kewensis and its fifteen supplements = Repertorio de los nombres genericos enumerados en el Index Kewensis y sus quince suplementos = Repertorium der im Index Kewensis und seinen fuenfzehn ersten Supplementen erwaehnten Gattungsnamen - Rouleau, Ernest 1916 -1991 (Châtelain, 1981)