Title: Correspondence
Subjects: Callitriche, Euphorbiaceae, Lemna, Scientific expeditions, Cruciferae, Echinocactus, Political and social views, Boundaries, Melocactus, Cereus, Nymphaea, Yucca, Nymphaeaceae, United States Naval Expedition to Japan (1852-1854), United States. Commission on Boundary between the Indian Territory and Texas, Correspondence, Opuntia, Botanical specimens, Description and travel, Wolffia, Mammillaria (Cactus), Onagraceae, Liliaceae, Pereskia, Callitrichaceae, United States, University of Cambridge
Places: United States, Bering Strait, Cuba, Pacific Northwest, Mexico
People: J. D. Graham (1799-1865), George Engelmann (1809-1884), William H. Emory (1811-1887), William Starling Sullivant (1803-1873), F. A. Wislizenus (1810-1889), Charles Wright (1811-1885), Ferdinand Lindheimer (1802-1879), John M. Bigelow (1804-1878), Augustus Fendler (1813-1883), John Torrey (1796-1873), Friedrich August Wilhelm Thomas (1840-1918), Asa Gray (1810-1888), Edward Tuckerman (1817-1886)