Title: Correspondence
Subjects: Correspondence, Opuntia, Botanical specimens, Euphorbiaceae, Fagaceae, Vitaceae, Liliaceae, Collection and preservation, Cereus, Pinaceae
People: Sereno Watson (1826-1892), J. B. Girard (1846-1918), George Engelmann (1809-1884), Valery Havard (1846-1927), J. Reverchon (1836-1905), Asa Gray (1810-1888)