108 



SILVA OF NOB Til AMEBIC A. 



PLATANACE-^. 



his connection with the United States and Me 



Boundary Survey. Originally confounded with 



Platanus racemosa^ it was first distinguished by Sereno Watson.^ 



In the deep and sombre canons of the Arizona mountains^ Platanus Wright 



IS a n 



oble 



d 



beautiful object^ rising high ab 



the Walnuts, Willows, and Alders which mark the course of the 



streams, with 



great wide-spreading p 



sea-green branches and bright foliage thrown into clear 



ef against the sunburnt hills covered with dark Evergreen Oaks and darker Pines 



1 



Watson (1826-92) was born at Windsor 



College. He devoted the remainder of bis life to a study of the 



iciit, and was graduated from Yale College in 1847 ; having flora of North America and to the care and development of the 

 taught school in different states, he studied medicine in the Uni- collections in his charge. In connection with Professor William 



versity of New York and later with an elder brother established at 



Wats 



the botanical portion of the 



Quincy, Illinois. He practiced his profession during two years only, report of the Geological Survey of California ; he was the author 



and then abandoned it to assume a business position in Alabama, of a Biographical Index of North American Botany, issued in 1878, 



where he resided from 1856 to 1861, beginning at this time the which unfortunately was not carried beyond the first volume, and 



study of plants, although it was not uutil several years later, after of numerous papers published in the Proceedings of the American 



a term in the Sheffield Scientific School, that he became a profes- Academy of Arts and Sciences, in which some twelve hundred spe- 



sional botanist. cies of North American plants were first described by him, and 



In 1868 Dr. Watson was appointed botanist of the United many difficult groups were elaborated. In 1890, with Professor 



States Geological Expedition which, under the leadership of Clar- J, M. Coulter, he published an enlarged edition of Gray's 



Manual 



ence King, explored the territory west of the Rocky Mountains of the Botany of the Northern United States. 



adjacent to the fortieth parallel of latitude. In 1871 he published, 



Serenoa^ <% genus of plants of the southern United States, estab- 



with the aid of Professor D. C. Eaton, his classical report upon the lished by the younger Hooker, commemorates th^ name of this 



plants he had collected on this expedition ; this led to his receiving modest and learned man, whose life was devoted to useful labor 



the appointment at Cambridge of assistant to Professor Asa Gray, and noble endeavor, 

 whom he succeeded as curator of the Gray Herbarium of Harvard 



EXPLANATION OF THE PLATE. 



Plate CCCXXIX. Platanus Wrightii 



1. A flowering branch, natural size, 



2. A stamen, enlarged. 



3. A pistil, enlarged. 



4. A fruiting branch, natural size. 



5. Vertical section of an akene, enlarged. 



6. A seed, enlarged. 



7. An embryo, enlarged. 



8. A winter branchlet, natural size. 



