BOTANY AT ST. LOUIS 



129 



Mississippi Valle3^ Seventeen years later, after an investigation of the 

 whole genus in the principal herbaria of this country and of Europe, 

 he published a systematic arrangement of all the Cuscutse, giving sev- 

 enty-seven species, besides a number of varieties. 



Dr. Engelmann's authority upon the CactacecE was of the very high- 

 est. He established the arrangement of these plants upon floral and 

 carpological characters. This work was carried on through a series of 

 papers beginning with his sketch of the botany of Dr. A. Wislizenus's 

 expedition from Missouri to northern Mexico, and continued in his 

 account of the giant cactus of the Grila, in his synopsis of the Cactacese 

 of the United States, and in his two memoirs upon the southern and 

 western species contributed to the Pacific Railroad Reports and to 

 Emory's " Report on the Mexi- 

 can Boundary Survey." He 

 had made preparations for a re- 

 vision of at least the Noith 

 American Cactacese, but upon 

 his death much knowledge of 

 this ditHcult group was lost. 



His papers on the American 

 oaks and the Coniferae are of 

 the highest interest, and are 

 some of the best specimens of 

 his botanical work; and the 

 same is also true of his study of 

 the vines. Nearly all that we 

 know of this genus scientifi- 

 cally is directly due to Dr. En- 

 gelmann's investigations. 



His work is characterized 

 by a minuteness and careful- 

 fulness of observation, coupled 

 with a nicety of discrimination 

 which made him a master in 

 S3^stematic work, his treatment 

 of the yuccas and agaves, the genera Juncus, siiphorhia, Sagittaria, 

 Isoetes, the Loranthacece, Sparganum and Gentiana giving him an 

 eminence among fellows botanists to which few attain. His name 

 was upon the rolls of many societies devoted to the investigation of 

 nature, and he was the recognized authority upon those departments 

 of his favorite science which had most interested him. His name 

 has been given to a monotypical genus of plants, Engelmannia, by 

 Torrey and Gray. Numerous species also bear his name. 



Shortly after Dr. Engelmann settled in St. Louis, Nicholas Riehl. 



FiG. 11. Nicholas Riehl ; 

 from a photograph kindly loaned by his son, 

 Mr. E. A. Riehl. ' 



