C. PARRYI. 203 



20. C. PARRYI NEVADENsis, but the whole herbage white, or at least gray, with a loose tomentum. West 

 end of Pcavine Mountain, Nevada, 1,600 m. elevation. Heller 10675 (UC). The same form grows also at Por- 

 tola, Plumas County, California, Johnston 2180 (UC). .\ccording to Johnston, the green and the white forms 

 grow intermingled both at Portola and at Keddie. Although no intermediates appear as to color, no other 

 distinguishing characters could be found. This appears to be a case of difference in a single character and per- 

 haps the result of mutation. The color is probably influenced by the amount of resinous matter secreted by 

 the stems and leaves. 



21. C. vuLCANicus Greene, Leaflets 1:80, 1904. — C. parryi vulcanicus. 



22. C. WYOMiNGENSis Nelson, Bot. Gaz. 28:372, 1899. — Not finally placed. The type specimens, from 

 Buffalo, Wyoming {Nelson 2^95), appear to be a variation from C. parryi typicm, the stems being leafy to the 

 top, the inflorescence elongated, and the bracts decidedly acuminate. But the leaves are narrow, the inflores- 

 cence reduced in size, and the flowers only 5 in the small head. The plants grew in strongly alkaline soil, which 

 may account for these modifications, or it is possible that detailed field studies will demonstrate wyomingensis 

 as a modification of some subspecies of C. nauseosus. Later collections from BufTalo {Nelson 8672), identified 

 as this, seem to be a form of C. nauseosus typicus, at least in part, the inflorescence being cymose and the bracts 

 only acute. 



23. LiNOSYRis BOLANDERi Gray, Proc. Am. Acad. 7:354, 1868. — C. parryi bolanderi. 



24. L. HowARDi Parry, in Gray, 1. c, 6:541, 1865.— C. parryi howardi. 



25. L. HOWARDI var. nevadensis Gray, 1. c. — C. parryi nevadensis. 



26. L. PARRYI Gray, Proc. Acad. Phila. 1863:66, 1863.— C. parryi typicus. 



27. Macronema BOLANDERI Greene, Leaflets 1:81, 1904. — C. parryi bolanderi, as to synonymy. The 

 probable reason for this transfer has been already discussed (p. 160). 



RELATIONSHIPS. 



The nearest relatives of Chrysothamnus parryi are undoubtedly to be sought among 

 certain forms of C. nauseosus, with which it has in common the notably pannose tomen- 

 tum of the twigs and similarly shaped corollas and style-branches. While the inflores- 

 cence is of the racemose rather than cymose type, individual heads are sometimes scarcely 

 distinguishable from those of nauseosus, except by the loosely arranged bracts. These 

 are always more attenuate in parryi and less distinctly ranked. While such characters 

 of the inflorescence and involucres serve well for specific distinctions, there can be no 

 doubt as to the common origin of the two stocks. 



Among the assemblage of forms here considered as constituting C. parryi, there is one 

 with an appearance so strikingly diff'erent from the others that it has not been heretofore 

 considered as conspecific with them. This is the original C. parryi, here made the basis 

 of subspecies typicus. It belongs to a portion of the Rocky Mountains where the only 

 other subspecies are howardi and its derivative attenuatus, both very diff'erent in appear- 

 ance. If it were not for the occurrence of intermediate forms in the mountains farther 

 west, parryi and howardi might both be maintained as major species. Their marked 

 difference, however, is based upon only vegetative characters, since all others, such as the 

 number and character of involucral bracts and flowers, exhibit complete series of inter- 

 gradations, as indicated in table 22, page 207. As compared with howardi, typical parryi 

 is a more robust plant, with wider and longer almost strap-shaped leaves and usually 

 larger heads. No intermediates in the leaf characters are found and the two are appar- 

 ently distinct where their ranges overlap. Farther west, however, we find such sub- 

 species as vulcanicus, with leaves as long as in typicus but narrow as in howardi; also 

 asper, with leaves as broad as in typicus but even shorter than in howardi; while in neva- 

 densis both length and width of leaf are sufficiently variable to satisfy a description of 

 either. Since none of these can be separated on other non-variable characters, they seem 

 to indicate that the whole gamut of forms is of a common and modern stock, which is best 

 accepted as a single major species. 



As in the case of typical parryi, every attempt has been made to find stable characters 

 for the specific separation of each of the described subspecies, but without success. None 

 of the characters heretofore used for the separation of species is of more importance than 

 those used in the key to the subspecies. Gray (Syn. Fl. 2' 136, 1884) describes the leaves 



