48 Trans. Acad. Sci. of St. Louis. 



American form8 uuder tomentosus. Grisebach in Fl. British 

 West Indies, considered scaber as represented in America, with 

 mollis and Carolinianus as distinct from it. Baker in Fl. 

 Bras, places both mollis and tomentosus under scaber. 

 Hemslev in Biol. Cent. Amer. Bot. unites tomentosus^ 

 Martii, mollis and Carolinianus under scaber. This last 

 must be considered as an extreme theoretical view. So far 

 as the not inconsiderable material in American herbaria is 

 concerned they are abundantly distinct with the possible 

 exception of Martii. 



Gray paved the way to a more critical separation of the 

 forms by the description of nudatus. But with nudatus 

 must be accepted several other forms in the United States 

 and numerous others in the West Indies, Mexico, Central and 

 South America, Africa and the Far East. The relationships 

 of some of our common forms are provisionally indicated 

 herein, but anything approaching this will be, for most of 

 the forms, absolutely impossible at present. It seems to the 

 author wholly immaterial at this juncture as to whether the 

 names represent good " species " or not. They represent 

 wonderfully distinct plant forms which must in any event 

 be recognized, no matter to what grade of relationship 

 they may eventually be assigned. It seems as if we would 

 arrive at some clear and comprehensive view of the genus 

 much sooner by means of clearly defined segregates than by 

 shuffling ofi" all responsibility in Hemsley's roomy aggregate. 

 More and more attention is being given our tropical flora, so 

 that many of the doubtful points will soon be cleared up. 



SPECIES OF THE UNITED STATES. 



These species, all of which occur east of the Rocky Moun- 

 tains, may be listed as follows : — 



1. Garoliniaims Willd. 



C= flexuosus Raf.). 

 Var. violaceus (Sch. Bip.). 

 2. tomentosus, L. 



(= Carolinianus var. simplex Nutt.) 

 Var. nudicanlis (Poir.). 

 (= nudicaulis Ell.). 



3. elatus Bertol. 



4. ntidatits Grav. 



