Rydberg : Rocky Mountain fi ora 55') 



ing synonyms: "Cnicus eriocephalus Gray, Carduus scopulorum 

 Greene I.e., C. Tiveedyi Rydb. I.e., C araneosus Osterh. * * * C. 

 Eatonii Gray, * * * C. canovirens Rydb. I.e. (?) C. pulcherrimtis 

 Rydb." Of these the two first are pure synonyms. Carduus Twee - 

 dyi is a related red-flowered species (see page 552). C. Eatoni, 

 as I understand it and Hmited to C. eriocephalus var. leiocephalus 

 D. C. Eaton, is a good species, forming a group by itself. C. arane- 

 osus is not related to C. scopidorum but to C. Parryi, as Oster- 

 hout suggested, and is probably a hybrid of that species and C. 

 erosus. C. canovirevs and C. pidcherrimus do not belong even 

 near C. scopidorum, but to the C. undulatus group. C. canovirens 

 has no very close relative. The nearest is perhaps C. canescens 

 (Nutt.). Nelson once thought it a good species, distributed it 

 under a manuscript name, and would have published it, if his 

 attention had not been called to the fact that it was already pub- 

 lished. C. pidcherrimus is most closely related to C. ochrocentrus 

 and stands to that species nearly in the same relationship as 

 C. undulatus does to C. megacephalus. 



Under Carduus foliosus are found the following synonyms: 

 C. scariosus (Nutt.) Heller and C. coloradensis Rydb. Judging 

 from Nuttall's original description of Cirsium scariosum, it is not 

 at all related to Carduus foliosus Hook. See remarks above under 

 C. lacerus. Carduus coloradensis is not to be referred to C. 

 foliosus. It was based mainly on Cnicus Drummondii of the 

 Synoptical Flora, and is apparently the same as Carduus Drum- 

 mondii of the New Manual, the corolla of which is described as 

 white. The original Cirsium Drtimmondii T. &G., oi which there 

 is a duplicate in the Torrey herbarium, has rose-purple corollas 

 The only specimens I have seen from the United States, are from 

 the Black Hills of South Dakota. All the others are from British 

 America. 



Carduus oreophilus Rydb. is given as a synonym under C. 

 Drummondii. From what is just stated it may be seen that it is 

 not the original C. Drummondii and a comparison between my 

 description in the Bulletin of the Torrey Botanical Club and that 

 of C. Drummondii in the New Manual shows that it is not C. 

 Drummondii as understood by Professor Nelson. C. oreophilus 

 is very local and many things suggest a hybrid, but I have failed 



