17() HOTANV 



cone 



is clearly defined, but iii some of my Southern forms of what lean 

 only consider as midHradiata that it is also slightly present—*, e., the style 

 branches are nol absolutely truncate. Whiki in the main I can recognize 

 marked differences between these two species, the widerangeof variation 

 in the rays, size, branching, etc., makes me regard the differences as in the 

 highest sense simply one of degree. It is noteworthy, too, that these two 

 forms appear to come nearer to each other as we go southward. 



Artemisia dracunculoides, Pursh.— Twin Lakes, Colorado (530); 

 also obtained from Arizona and Utah. 



Artemisia borealis, Pallas.— South Park, Colorado (535, 536). Alpine. 



Artemisia canadensis, Michx. — Arizona ; also from Colorado (532). 



Artemisia tridentata, Nutt.— Twin Lakes, Colorado (431) ; also from 

 the New Mexican deserts, Loew. 



Artemisia discolor, Dougl. — Southern Arizona (753). 



Artemisia Ludoviciana, Nutt— Colorado (529) Arizona, by the earlier 

 explorations of the Survey, and later by Loew from Mount TurnbulL The 

 latter specimen looking toward var. Mexicana, Gray, having the upper leaves 

 trifid and the margins revolute, and the entire plant (especially younger 

 specimens) tonientose-canescent. From the San Luis Valley, Colorado, 

 we have, in 1873 (539), a much narrower-leaved form (tenuifolia, Gray), 

 which Dr. Gray intimates may be a distinct species. 



Var. Douglasiana, D. C. Eaton, is from Southern Arizona (717) and 

 from Utah. Varieties latiloba, Nutt., and latifolia, T. & G., also from Utah. 



Artemisia frigida, Willd. — From plains between Denver, Colo., and 

 the foot-hills (4G9). To this we frequently find AphyUon fasciculatum, T. 

 & G., attached ; parasitic attachments uniting the rootlets of the two. 



Artemisia scopulorum, Gray.— South Park, Colorado (430). Alpine. 



Arnica cordifolia, Hook.— Clear Creek, Colorado (570). 



Arnica alpina, Lacstad. (Arnica angustifoUa, Vahl.)— Clear Creek, 

 Colorado (569). 



Arnica latifolia, Bongard. — Utah. 



Arnica longifolia, D. C. Eaton. — Utah. 



Arnica foliosa, Nutt. — More than a foot high, erect, simple, tomen- 

 tose or glandular-pubescent; lower leaves petioled ; upper ones sessile, 



