Robinson: Polycodium 551 



Yet, taken on a summary of characters, there is probably no 

 species found in Louisiana that is more likely to have been the 

 basis for Robin's description than Gaylussacia dumosa (Andr.) 

 A. Gray. 



All of the remaining species of the family found north of the 

 Mexican border are retained by many authors in Vaccinium. 

 Generic or sectional segregation has been proposed on several 

 characters, taken singly or in combination, the degree of union 

 of the corolla, its aestivation, its shape, the presence or absence of 

 awns on the anthers, the presence or absence of pubescence on the 

 filaments, the presence or absence of false partitions in the ovary, 

 the nature of the inflorescence, and tetramerous as contrasted 

 with pentamerous flowers. 



In the Thibaudieae, the other subfamily of Vacciniaceae, 

 general agreement has been reached that the primary basis of 

 differentiation should be sought in the stamens. There is much 

 reason to believe that this is equally true with regard to the 

 Vaccinium group, but it would be useless to belittle the fact that 

 the weight of botanical opinion has been otherwise. The most 

 popular segregate has been Oxycoccus, from which Hugeria has 

 further been discriminated. They differ from the remainder of 

 the group and from one another in the degree of division of the 

 corolla. Possibly Polycodium will prove the most acceptable 

 of the others. But on what grounds should it be retained? 

 Professor Greene's claims for it are excessive, although indefinite, 

 for he does not define "genuine Vaccinium." It has a campanu- 

 late corolla: so have V. arboreum Marsh.,* V. Vitis-Idaea L., V. 

 poasanum Donn. Sm., V. confertum H. B. K., and others, differing 

 from one another in various characters, and none except the first 

 closely allied to Polycodium. The 10 stamens of Polycodium have 

 pubescent filaments and 2-awned anthers: except in number they 

 differ from the great majority of species of the eastern and southern 

 United States, which have pubescent filaments but awnless 

 anthers (section Cyanococcus), from most of those of the western 

 States, which have 2-awned anthers but glabrous filaments (section 

 Euvaccinium), but agree with many tropical American species, 



* No opinion is necessarily expressed in giving the name of this or any other 

 species as Vaccinium. 



