OF ARTS AND SCIENCES. 257 



XII. 



CONTRIBUTIONS TO THE BOTANY OF NORTH 



AMERICA. 



By Asa Grav. 



Commuaicated October 8th and December 10th, 1884. 



1. A Revision of some Borragineoiis Genera. 



Tnis revision has become necessary by some recent discoveries, and 

 by a more thorougli study and appreciation of the characters of the 

 various plants which have been referred, first by the De CaudoUes 

 and afterward by Dr, Torrey and myself, to the genus Eritrichium. 

 It is not pleasant to find that the conclusions now reached require 

 considerable changes of accepted names which have received the 

 sanction of the late Mr. Bentham in the recent Genera Plautarum, 

 and that these changes might have been made or anticipated several 

 years ago. But if it needs be so, the sooner they are made the 

 better. 



It plainly appears that too much lias been made of the degree of 

 obliquity of the nutlets, of their extension above the gynobase, and of 

 the extent of their«attachment to it, or, which is nearly the same thing, 

 of the amount of growth, if any, of the developing nutlets above or be- 

 low then- insertion upon the more or less elevated axis (gynobase) which 

 intervenes between the common torus and the style.* It seems to me 

 equally clear that there are too great differences from species to species 

 in Echinospermum., Cynoglossum, Omphalodes, Eritrichium, and the 

 various plants which have been referred to these genera, to justify the 

 two tribes Cynoglossece and Eritrichie(2. So that, indeed, it seems 

 necessary to follow De CandoUe in this respect, by referring all the 

 quadrinuculate genera with lateral or introrse-basal insertion of the 

 nutlets to the Cynnrjhssece, to be divided into sections as well as may 

 be practicable. This tribe sliould even include Moltkia {ccendea)^ 



* As Turczaninow long ago rightly expressed it, all the part to wliicli the 

 nutlets are attached is gynobase, wlietlier it be depressed, pyramidal, conical, or 

 subulate, or even filiform. Only the free portion above is the style. 



VOL. XX. (n. S. XII.) 17 



