Rapid biological inventories - Field Museum of Natural History. Environmental; Conservation Programs. (Field Museum, 2006)

Rapid biological inventories - Field Museum of Natural History. Environmental; Conservation Programs. (Field Museum, 2007)

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

Rare and endangered vascular plant species in Massachusetts : as abridged from Coddington and Field, 1978 - Massachusetts. Dept. of Environmental Management. (Massachusetts Dept. of Environmental Management], 1979)

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)

Rare native plants of Massachusetts - Massachusetts. Division of Fisheries; Wildlife. (Division of Fisheries and Wildlife, 1989)

Rare native plants of Massachusetts - Massachusetts. Division of Fisheries; Wildlife. (Massachusetts Division of Fisheries and Wildlife, 1987)

Rare native plants of Massachusetts - Massachusetts. Division of Fisheries; Wildlife. (Massachusetts Division of Fisheries and Wildlife, 1985)

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

Reevaluation of vegetational characteristics at the CERC Field Research Facility, Duck, North Carolina - Coastal Engineering Research Center (U.S.). Field Research Facility. (The Center, 1983)

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)

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)