|From the P.n letin Ol the Tokkey Botanical Cub, 32 : 597-610. 1905 ] 



Studies on the Rocky Mountain flora — XV 



Per Axel Rydberg 



In preparing my Flora of Colorado, to be issued as a Bulletin 

 from the Agricultural College at Fo^ Collins, Colorado, and now 

 in press, I have found it necessary to change the nomenclature of 

 a number of species. As the scope of the Flora comprises only 

 keys to the families, genera and species, and an enumeration of 

 localities where specimens have been collected, it has been impos- 

 sible to include therein any fuller synonomy with citations, or 

 any discussions. It has, therefore, seemed advisable to make the 

 publication of these changes and notes elsewhere. 



Caryopitys monophylla (Torr. & Frem.) Rydb. 



Pinus monopkyllus Torr. & Frem. Rep. 319. 1845. 



Dr. Small in his Flora of the Southeastern United States has 

 followed the more modern views in dividing genera, which consist 

 of very natural sections or subgenera, into as many separate 

 genera. The genus Pinus as usually treated contains at least four 

 distinct subgenera, better defined and more easily distinguished 

 from each other, than for instance Picea and Tsuga. Three ot 

 these had already generic names, viz.: Pimis L. (proper), Apinus 

 Necker and Strobus Opiz. Dr. Small had to give the fourth 

 group, which is wholly American, a new name, Caryopitys. In 

 the Rocky Mountain region the genus is represented by the type 

 species C. ednlis (Engelm.) Small, and by the species given above. 

 One of the four genera is not represented within the area covered 

 by Dr. Small's work, viz.: 



Apinus Necker, Elem. Bot. 3: 269. 1790 



Most of Necker's genera are hard to determine, but in this 

 case Necker not only gives the characters by which he distin- 

 guishes the genus from Pinus proper, but also cites two species, 

 viz.: cembra and pinea. In the Kew Index, the genus is given, 

 but no species are mentioned. The way in which Necker makes 



597 



