RypBERG: STUDIES ON THE Rocky Mountain FLORA 21 
Troximon grandiflorum tenuifolium, and points out the characters 
distinguishing it from T. grandiflorum. He gives as a synonym 
Siylopappus laciniatus 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 
Stylopappus 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- 
tatus 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 Macrorhyn- 
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 7. 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. letospermum the leaves are 
broadly oblanceolate and the calyculate bracts are in 2 or 3 series 
and with spreading tips, as in 7. dumetorum. 
Lactuca L. 
Professor Nelson has given a new specific name to the more 
common prickly lettuce of the Rocky Mountain region. It has 
