BOT.— Vol. I.] EASTWOOD— STUDIES FROM THE HERBARIUM. 1 25 



It is very doubtful if the genus Synthyris will stand in 

 the future as it is now set forth in the Synoptical Flora; 

 nor is it more certain that Professor Greene's transferrence 

 of all the species to Wulfenia will be final. ^ In a group of 

 genera so closely related and so polymorphous as those 

 included under subtribe Veronice^e in Bentham and 

 Hooker's Genera Plantarum, botanists will always differ in 

 regard to generic limits. 



A difference in the arrangement of the leaves and habit 

 of growth primarily separated Wulfenia from Veronica; 

 the form of the corolla, the number of calyx divisions, the 

 dehiscence of the anthers and the shape of the seeds sep- 

 arated Synthyris from Wulfenia. Professor Greene has 

 shown the worthlessness of considering the number of 

 calyx divisions as a generic character, and his position is 

 reinforced by the two new species described in this paper 

 and by two described under Wulfenia by Aven Nelson.^ 

 Professor Greene, however, does not give a diagnosis of 

 Wulfenia nor tell why it, also, should not be included 

 under Veronica. 



If habit of growth is taken as a generic distinction, then 

 Synthyris naturally falls into two genera, one containing 

 S . rotundifolia and S . reniformis; the other, the remain- 

 ing species and perhaps the original Wulfenia. If other 

 characters are to be taken, many genera would result and 

 the synonymy become much involved. It seems simplest 

 to follow Bentham and Hooker and Gray and leave these 

 uncertain problems to the future; so the new species of 

 the Colorado mountains have been described as Synthyris. 



1 Erythea, Vol. II, p. 80. 



2 Torr. Bull., Vol. XXV, pp. 281, 282. 



