12 



The minutes of the meeting of October 14 were read and 

 approved. 



Dr. E. G. Arzberger, Bureau of Plant Industry, Washington, 

 D. C, was nominated for membership. 



Dr. H. H. Rusby on behalf of the committee to prepare a 

 suitable memorial of Judge Addison Brown submitted a bio- 

 graphical sketch which was, on the motion of Professor R. A. 

 Harper, referred to the board of editors for publication. 



The resolutions relating to the death of Judge Brown and E. L. 

 Morris were ordered engrossed and sent to the families of the 

 deceased. 



The first number of the scientific program was a paper on the 

 Ambrosiaceae. 



Dr. Rydberg presented some preliminary remarks on the results 

 of his investigations of the family Ambrosiaceae of which he is 

 preparing a monograph for the North American Flora. His 

 work has been ■ confined to the Ambrosiaceae proper. This 

 group is represented in the eastern United States by the genera 

 Ambrosia and Xanthium. These two genera were the only ones 

 known to Linne when he wrote his Species Plantarum. The 

 characters distinguishing the two are the following: 



In Ambrosia the bracts of the staminate heads are united. The 

 pistillate head contains usually only one flower and forms a bur 

 with a single beak which is 3- or 4-toothed at the apex and very 

 little oblique. The bur is armed with a single circle of small 

 straight spines. In Xanthium the bracts of the staminate heads 

 are distinct. The pistillate head develops into a bur with nu- 

 merous hooked spines and two beaks which are very oblique at 

 the mouth and have only 2 lobes, of which the outer one is much 

 longer and usually hooked. The younger Linnaeus described 

 in the Supplementum Xanthium fruticosum, which disagrees 

 with the whole genus in having the bracts of the staminate heads 

 united as in Ambrosia. 



Medicus claimed that the older Linnaeus had included this 

 species in Ambrosia, which statement has been impossible to 

 verify. Medicus in Act. Acad. Theod. Palat. 3: 247. 1775 dis- 

 cusses this species, still including it in Ambrosia, but suggests 



