CONTRIBUTIONS TO NORTH AMERICAN 

 EUPHORBIACEAE V* 



BY 

 CHARLES FREDERICK MILLSPAUGH 



1. "EUPHORBIA ADENOPTERA" IN 

 NORTH AMERICA 



M. Boissier, in his treatment of the species of Euphorbia in De 

 Candolle's Prodromus, grouped all North American specimens that 

 bore the vespertilloid involucral appendages characteristic of Euphorbia 

 dioica Kunth under Bertoloni's Euphorbia adenoptera, retaining the 

 latter name solely because Kunth's species proved to be monoecious. 



In the light of a large amount of material collected since M. Bois- 

 sier's consideration of the genus, it is evident that Bertoloni labored 

 better than he knew, his adenoptera being good and in no way conflicting 

 with Kunth's dioica. Herr Klotzsch, and later Herrn Klotszch u. 

 Garcke saw with keen perception that there were several distinct species 

 that bore a general likeness; these, however, M. Boissier did not recognize 

 and so compiled his description of adenoptera as to include at least 

 some characters of each. 



Through the kindness of Dr. Engler, Dr. Prain, Dr. Casimir de 

 Candolle and M. Beauverd, I have been granted the privilege of 

 studying the types of dioica, adenoptera, densiflora, inaequalis, Lin- 

 deniana and other material from the herbaria of Kew, Berlin, Boissier 

 and De Candolle; these, with the large series in the herbarium of the 

 Field Museum and the specimens in the collections of the Missouri 

 Botanical Garden, New York Botanical Garden, United States National 

 Herbarium and the Gray Herbarium, Cambridge, all of which have 

 been courteously loaned me, have rendered the following solution of 

 the group possible. 



The North American "adenopterae" resolve into eight clearly 

 characterized species which may be summarized as follows: 



"Contribution I appeared in Proc. Calif. Acad. ser. 2, 2:217-230. 1889. 

 II Pittonia 2 182-90. 1890. 



III Botanical Gazette 25:13-25. 1898. 



IV Botanical Gazette 26:265-270. 1898. 



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