STUDIES IN CEANOTHUS. I75 



perfectly known, and it will be many years before the 

 species are even approximately settled. The set of about 

 a hundred forms studied in the field by the writer and 

 distributed to the principal herbaria of the United States 

 is apparentl}^ the first attempt to bring these variations, 

 with the necessary notes, to the attention of botanists. It 

 has been too much the rule with collectors to neglect these 

 connecting forms and gather only the typical or the ex- 

 tremes. Imperfect as this set is it must convince every 

 unprejudiced student of the genus that there are already 

 far too man}' accepted. All the new species recently 

 proposed are intermediates between species themselves 

 doubtfully separated by slight and inconstant characters. 



The species of Ceanothus are distinguished almost 

 entirely b}^ leaf forms. There is no. constant character 

 of fruit or flower b}^ which any one of the species can 

 be separated from others of the same section. The habit 

 is so readily modified by environment as to be of small 

 value. The character of penninervate or trinervate 

 leaves which has been used to divide the Euceanothi 

 fails completely. The presence or absence of marginal 

 glands is not to be trusted, and the pubescence is ad- 

 mitted to be variable; many of the species, as C. veluti- 

 nus, C . cordiilatiis, C. arborcns, C . thyrsijlortis, C . Fend- 

 leri, etc., having as now known glabrous as well as pu- 

 bescent forms. 



All the species north of Mexico bloom in the spring — 

 in the latitude of Central California, at moderate eleva- 

 tions, from March till May. At elevations of 5,000- 

 8,000 feet, from June to August. Along the Coast they 

 often begin to blossom sparingly in January. All the 

 western species bloom from the old wood, but often 

 continue blooming on the new shoots. The inflorescence 

 is axillary, the leafy peduncular shoot which in some 



