64 BOTANICAL GAZETTE [january 



''integerrima," while most of them in the specimen before me show 

 a distinct but fine glandular denticulation in the lower half. Those 

 of the type are entire, with the exception of a few minute teeth at 

 the base of some leaves. They lack stomata in the upper epidermis. 

 If I had seen the type before I finished the manuscript of this 

 article, I would have placed S. glacialis next to 5. ovalijolia, but 

 as long as the male flowers are unknown the true affinity remains 

 unknown. 



31. S. VENUSTA And. in DC, Prodr. 16^:288. 1868, non Host 

 1828, from Sitka, of which, according to Coville, the description 

 ''suggests that the plant may prove to be a form of Salix reticulata 

 grown in a shaded situation," can only be judged by an examination 

 of the type material, which I have not yet had the opportunity 

 to see. 



32. S. OBCORDATA And. in DC, Prodr. 16^:291. 1868, which, like 

 the preceding, came from Sitka, is even more obscure than that, and 

 may prove to be another S. reticulata form or a hybrid of it with 

 some other species. Andersson himself placed it without number 

 as S. ohcordata between S. ovalifolia and S. furcata, but he says 

 nothing about its relationship to these species, only mentioning its 

 resemblance to S. venusta and 5. reticulata in his more than meager 

 description. 



I hope that my notes may prove useful to other students of 

 American willows, and I shall be most thankful to anyone who can 

 correct any mistake I have made or furnish me with good material 

 or information of these or other American willows. There are, of 

 course, quite a number of specimens before me which I have not 

 yet been able to elucidate. Among them are many which I suspect 

 of being of hybrid origin, but I do not intend to deal with the hybrids 

 until I have gained a more thorough understanding of all the 

 American forms of this difficult genus. 



Arnold Arboretum 

 Jamaica Plaesj, Mass. 



