462 Rydberg : Rocky Mountain flora 



under A. columhiana: "It can not be referred to A. Chamissonis, 

 since it lacks the distinctly obovate leaf-cut, the broad, short disk- 

 corollas and the tawny subplumose pappus of that species." 

 These characters belong to A. mollis, not to A. Chamissonis. 



There are more exceptions to be made to the treatment in 

 the New Manual. Under Arnica ventorum Greene are given as 

 synonyms A. platyphylla A. Nels. and A. grandiflora Greene. I 

 have not seen the type of A. platyphylla, but A. grandiflora Greene 

 is closely related to A. cordifolia Hook., and is not of the A. lati- 

 folia group. One specimen collected by R. S. Williams and re- 

 ferred to A. platyphylla by Nelson in his original publication is 

 exactly like a specimen sent to Dr. Torrey as A. Menziesii by 

 Dr. Hooker and included by him in his Flora. Both of these are 

 very close to the original Arnica latifolia Bong., of which there 

 is a duplicate in the Torrey herbarium. The only essential dif- 

 ference is that A. latifolia has perfectly glabrous achenes, while 

 in A. Menziesii and Williams' plant the achenes have a few scat- 

 tered hairs toward the upper end and are sparingly glandular-gran- 

 uliferous. 



Arnica sylvatica Greene is made a variety of A. suhplumosa, 

 and specimens distributed from the University of Wyoming under 

 the name Arnica suhplumosa sylvatica are nothing but a low- 

 stemmed A. suhplumosa. But the original A. sylvatica, of which 

 there are two duplicates in the herbarium of the New York 

 Botanical Garden, is quite different. It has cordate basal leaves 

 and coarsely and saliently toothed stem-leaves. It is related to 

 A. diver sifolia Greene {A. latifolia viscidida A. Gray). 



Professor Nelson has also united Arnica fulgens Pursh and A. 

 pedunculata Rydb. What the original A. fulgens was, I do not 

 really know, as I have not seen Bradbury's specimen; but A. 

 fulgens, as interpreted by myself and by Piper,* has a horizontal 

 slender rootstock, without any tufts of brown hairs, while A. 

 pedunculata, including A. monocephala Rydb., is characterized by 

 its short, thick, almost erect rootstock, with dark brown hair- 

 tufts in the manner of Plantago eriopoda. It is the only species 

 in North America that has this character, so far as I know. 



*Contr. U. S. Nat. Herb. 11: 590 and 592. 



