1 62 DAVENPORT ACADEMY OF NATURAL SCIENCES. 



THE NORTH-AMERICAN GENUS, CEANOTHUS, 



With an Enumerated List, and Notes and Descriptions of Several Pacific 



Coast Species. 



BY C. c. PARKY. 

 {Read lefore the Academy, Decern I er 28, /S8S.) 



Since the important additions to the exclusively North American 

 genus, Cednothus, L. made by the discoveries of Mr. Nuttall, on the 

 Pacific coast, over fifty years ago (1836), and published in Vol. I., 

 Flora of North America, nearly all the systematic work undertaken 

 in defining species and arranging them in natural groups, has been 

 mainly based on the fragmentary specimens accumulated in the large 

 herbaria, remote from the region where they reach the fullest develop- 

 ment. 



The latest revision (not yet completed), by Professor Trelease, of the 

 Shaw School of Botany, at St. Louis, Missouri, and published in the 

 Proceedings of the California Academy of Sciences, Vol. I., 2d Series, 

 pp. 1 10- 1 18, enumerates thirty-two species, all but six of which belong 

 to the Pacific coast district. This interesting synoptical list, embody- 

 ing the latest results of herbarium stud) r , and bringing together, in com- 

 pact form, the scattered literature of this genus, shows, no less plainly, 

 the lack of personal field observations, which would have helped to 

 solve many of the dubious points here brought to view, the difficulties 

 of which none can so well appreciate as the author himself. 



With the present writer, whose field observations on the Pacific coast 

 now cover a period of forty years, a growing interest has been felt, as 

 renewed opportunities have offered for investigating, in their native 

 haunts, the varied forms of this attractive genus; and, during the past 

 decade, special attention has been given, by copious collections and 

 field notes, to elucidate this subject in its strict botanical relations, some 

 of the results of which are hereby presented, for the first time : 



GENERAL OBSERVATIONS. 



As a natural genus of plants, since its separation from the allied 

 Rhamnaceous genera with which it was combined by Linnaeus, it pre- 



