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 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)

Rare plant inventory of the outstanding natural areas of the Rocky Mountain Front - United States. Bureau of Land Management. (Montana Natural Heritage Program, 1988)

A rare plant survey of the Wainwright Dunes Ecological Reserve - Alberta. Alberta Sustainable Resource Development. (Alberta Sustainable Resource Development, Resource Data Branch, Public Lands Division, 2003)

Rare plants of New York State - Mitchell, Richard S., 1938 - (New York State Museum, University of the State of New York, State Education Dept, 1981)

Reading Naturalist. Reading - Reading Natural History Society.

Reading Naturalist. Reading - Reading Natural History Society. (2013)

Realizing nature's potential : proceedings of the William L. Brown Symposium honoring Dr. Gordon Cragg - Miller, James Stuart, 1953 - (Missouri Botanical Garden, 2011)

Recognizing plant families of the west : field guide - United States. Bureau of Land Management. (U.S. Department of the Interior, Bureau of Land Management, 2021)

Record of decision and Lake Havasu Field Office approved resource management plan - United States. Bureau of Land Management. (U.S. Department of the Interior, Bureau of Land Management, Lake Havasu Field Office, 2007)

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

Records of the Australian Museum - Australian Museum (Printed by order of the Trustees, 2001)

Records of the Australian Museum - Australian Museum (Printed by order of the Trustees, 2012)

Records of the Australian Museum - Australian Museum (Printed by order of the Trustees, 2013)

Records of the Australian Museum - Australian Museum (Printed by order of the Trustees, 2018)

Records of the Queen Victoria Museum Launceston - Queen Victoria Museum (Launceston, Tas.) (The Museum, 1996)

Records of the Queen Victoria Museum Launceston - Queen Victoria Museum (Launceston, Tas.) (The Museum, 2003)

Records of the Western Australian Museum - Western Australian Museum (Western Australian Museum, 1990)

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, 2003)

Records of the Western Australian Museum - Western Australian Museum (Western Australian Museum, 2004)

Records of the Western Australian Museum - Western Australian Museum (Western Australian Museum, 2009)

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)

Red list of the endemic plants of the Caucasus : Armenia, Azerbaijan, Georgia, Iran, Russia, and Turkey - Missouri Botanical Garden. (Missouri Botanical Garden Press, 2014)

Redescription of Strophopoda aprica Van Duzee and the description of two new genera and five new species from the southwestern United States and northern Mexico (Heteroptera, Miridae) - Schwartz, Michael D. (American Museum of Natural History, 2005)

Rediscovery of the Australian pollen wasp Metaparagia doddi (Hymenoptera, Vespidae, Masarinae) - Davidson, Amy R. (American Museum of Natural History, 2009)

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)

Reisen in den Vereinigten Staaten, Canada und Mexico - Müller, J. W. von Baron (Johann Wilhelm) 1824 -1866 (F.A. Brockhaus, 1864)

The relationship between Aeschynomene americana L. and root-knot nematodes (Meloidogyne spp.) - Hardy, Stephanie Randa L., 1960 - (1986)

Releases of beneficial organisms in the United States and territories, 1983 - United States. Agricultural Research Service. (U.S. Dept. of Agriculture, Agricultural Research Service, 1994)

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)