Rydberg : Studies ox the Rocky Mountain flora 21 



Troximon grandiflorum tenuifolium, and points out the characters 

 distinguishing it from T. grandiflorum . He gives as a synonym 

 Stylo pap pus lac in in tits longifolius Nutt., but a duplicate of the 

 type of the latter collected by Douglas is in the Columbia Univer- 

 sity herbarium and in this specimen the outer bracts are not dilated 

 as they are in A . grandiflora and its relatives. 



In the Proceedings of the American Academy, vol. 19, Dr. 

 Gray adopts the name Troximon laciniatum, giving as synonyms 

 Stylo pappus laciniatus Nutt. and its variety longifolius; also Troxi- 

 mon grandiflorum var. tenuifolium and var. laciniatum of the Botany 

 of California. A duplicate of Nuttall's type of Stylopappus lacin- 

 iatus is also in the Columbia University herbarium. In later 

 years many specimens matching this specimen have been collected 

 in Wyoming, Colorado, Utah, and Idaho. This is a species with 

 achenes of the type of Agoseris glauca and was probably included 

 in Gray's Troximon glaucum laciniatum, but it is not Macrorliyn- 

 chus glaucus laciniatus D. C. Eaton. In my Flora of Colorado, 

 I adopted the name Agoseris laciniata (Nutt.) Greene for this 

 species. Professor Aven Nelson describes it in the New Manual 

 as Troximon arachnoideum (Rydb.) A. Nels. It has nothing to 

 do with Agoseris arachnoidea Rydb. See above, p. 18. 



Taraxacum 

 Professor Nelson's treatment of Taraxacum is good. He ac- 

 knowledges six species, instead of only one as Dr. Gray did. The 

 only criticism I have to offer is that Taraxacum leiospermum 

 Rydb. is made a synonym of T. angustifolium Greene. It is 

 true that in both the lower part of the achenes is smooth, but 

 otherwise there are several discrepancies between the descriptions 

 of the two. T. angustifolium is characterized as having narrow, 

 oblong-linear leaves, and the outer bracts few and small, in a 

 single series, and erect, while in T. leiospermum the leaves are 

 broadly oblanceolate and the calyculate bracts are in 2 or 3 series 

 and with spreading tips, as in T. dumetorum. 



Lactuca L. 



Professor Nelson has given a new specific name to the more 

 common prickly lettuce of the Rocky Mountain region. It has 



