NORTH AMERICAN SPECIES OF CEANOTHUS. 115 



cles) subcorymbose inflorescence of blue flowers — those of 

 integerrimiis appearing to be always white. 



C. arboreiis is, as Professor Greene has shown, the largest 

 of our species. It was collected on Sta. Catalina many 

 years ago, by Nuttall, who notes its arboreous habit on the 

 label accompanying a specimen in the herbarium of the 

 Philadelphia Academy. 



Numbers 14 to 17 of the list are quite difficult to dis- 

 tinguish. 



C. incanus, with large, rather thin, nearly smooth ellip- 

 tical leaves, often rounded in abruptly to the lateral nerves, 

 a short distance above ths base, usually entire, pale below; 

 ratiier large white flowers (often 5 or 6 mm. in expanse); 

 and large depressed fruit with a more fleshy exocarp than 

 usual, is generally recognized without much difficulty. The 

 same is true of C. eglandulosas, which is nearly glabrous and 

 very glaucous, with rather small strongly ovate entire or 

 nearly entire leaves, usually brown above, in herbarium 

 specimens ; and smaller dingy blue flowers. But divaricatus 

 and cordulatus approach each other so closely that it is hard 

 to draw the line between them. The specimens with smaller, 

 thicker leaves are commonly referred to the latter, as being 

 evidently what Kellogg figured, while the former species 

 usually has large and more flexible leaves. 



C. Fendleri, with rather thin narrower leaves, silky-can- 

 escent in the type, greea and nearly glabrous in the variety; 

 stands out quite well from its congeners, in geographical 

 distribution, also. 



C sorediatiis is a species which I do not at all understand. 

 As it is here accepted, it includes plants with slender rather 

 simple twigs, and others that are quite rigid and intricately 

 branched; the leaves of some are very broadly ovate, while 

 others are narrower; and the pubescence varies from silky 



