In 1849 Dr. Engelmann published, in the "Memoranda of the American Academy of Arts and Sciences," the "Plantæ Fendlerianæ," thereby, says his biographer in the St. Louis "Universe," "drawing from obscurity another German-American botanist, August Fendler." Fendler and he had become acquainted on a governmental expedition to the Rocky Mountains, to which the former was attached as engineer. He was afterward engaged for two years, upon Engelmann's recommendation, in classifying and arranging the Henry Shaw collections of plants. He traveled in the Rocky Mountains, California, Mexico, Central America, and Brazil, and died in the Island of Trinidad in 1882. His name, the "Universe" adds, can not be forgotten in the history of the American flora. A number of plants are named after him, among them one of the handsomest cactuses, the Cereus Fendleri.
Dr. Engelmann's work upon the cactus family is styled by Dr. Gray, in the "American Journal of Science," most extensive and important, as well as particularly difficult, and his authority the highest. "He essentially for the first time established the arrangement of these plants upon floral and carpological characters." This work was begun in the report of the Doniphan expedition, and was continued, by his account in the "American Journal of Science," in 1852, of the giant cactus of the Gila (Cereus giganteus) and an allied species; "by his synopsis of the Cactaceæ of the United States, published in the 'Proceedings of the American Academy of Arts and Sciences,' 1856; and by his two illustrated memoirs upon the Southern and Western species, one contributed to the fourth volume of the series of 'Pacific Railroad Expedition Reports,' the other to Emory's 'Report on the Mexican Boundary Survey.' He had made large preparations for a greatly needed revision of at least the North American Cactaceæ. But although his collections and sketches will be indispensable to the future monographer, very much knowledge of this difficult group of plants is lost by his death. Upon two other peculiarly American groups of plants, very difficult of elucidation in herbarium specimens, Yucca and Agave, Dr. Engelmann may be said to have brought his work up to the time. Nothing of importance is yet to be added to what he modestly styles 'Notes on the Genus Yucca' published in the third volume of the 'Transactions of the St. Louis Academy,' 1873, and not much to 'Notes on Agave' illustrated by photographs, included in the same volume and published in 1875."
Other special works mentioned by Dr. Gray are those on Juncus, in the second volume of the "Transactions of the St. Louis Academy"; Euphorbia, in the fourth volume of the "Pacific Railroad Reports," and in the "Botany of the Mexican Boundary"; Sagittaria and its allies; Isoetes; the North American Loranthaceæ Sparganium; certain groups of Gentiana; and some other genera. "Of the highest interest, and among the best specimens of Dr. Engelmann's botanical work,
