RvDBERG : Studies on the Rocky Mountain Flora 620 



arran"-ement of the involucral bracts in distinct vertical rows. It 

 grows in gravelly places in northern Wyoming, at an altitude of 

 2000-2500 m. 



SIDERANTHUS Fraser 



The name SidcrantJius appears first in Fraser's Catalogue, but 

 there only as a nomen nudum. Pursh in his Flora on page 750 gives 

 Siderantlms integrifolius Fraser and 5. pinnatifidiis Fraser as syno- 

 nyms oi Amcllus villosus and A. spinulosiis described on page 564. 

 There may be a doubt as to which of these should be regarded as 

 the type of Siderantlms. Ajiwllns villosus with its relatives was 

 made a genus CJirysopsis by Nuttall in 1818 or by Elliott in 

 1824, according to different interpretations, long before Eriocavpwn 

 was established (1840). This leaves SiderantJius pi/iiiatifidiis as 

 the residue of the genus Sideranthus. Besides Nuttall, who was 

 the real author of Fraser's Catalogue, made Sideranthus a subgenus 

 of Dieteria containing the only species D. spinulosa {Aplopappiis 

 spinulosus DC. See Trans. Am, Phil. Soc. II. 7 : 301) ; and thus 

 shows that he regarded it as the type of Sideranthus.^ 



Leaves spinescent toothed, not pinnatifid. 



Heads discoid ; perennial with woody caudex. i. S. grindelioides. 



Heads radiate ; annual. 2. S. rubiginosus. 



Leaves pinnatifid. 



Stem more or less fioccose, or cinereous especially when young. 



Plant cinereous pubescent, more or less glandular. 3. S. australis. 



Plant more or less floccose, not at all glandular. 4. .S". spinulosus. 



Plant neither floccose nor cinereous. 



Plant perfectly glabrous or sparingly glandular puberulent. 



5. S. glaberrimus. 

 Plant finely puberulent. 



Heads hemispherical ; bracts slightly glandular. 6. S. puberulus. 



Heads somewhat turbinate ; bracts densely glandular puberulent. 



7. S. turbinellus. 



I. Sideranthus grindelioides (Nutt.) Britton 



Eriocarpujn grindelioides Nutt. Trans. Am. Phil. Soc. II. 7 : 

 321. 1840. 



Aplopappus Nuttallii Torr. & Gray, Fl. N. A. 2 : 240. 1842. 



* Professor Greene (Pittonia 2 : 115) seems to think Sideranthus is derived from 

 the Latin sidiis, star, and the Greek, avi?of, flower. It is better to regard the first part 

 also as Greek, ai6r/pog, iron. Why accuse Nuttall of making a hybrid word, which 

 we would not permit ourselves ? 



