RYDBERG: Rocky MounrAIN FLORA 553 
Carpuus BuTLERI Xx KELSEYI 
The leaves of the two supposed parents are very similar, so 
the differences are mostly found in the inflorescence ‘and the in- 
volucral bracts. See under the description of Carduus Butleri. 
The supposed hybrid has the inflorescence of C. Kelseyi, the 
bracts of C. Butleri, but slightly arachnoid-hairy. 
Montana: Rost Lake, July 28, 1908, Butler 703. 
Carduus Butleri was collected at the same locality and on the 
same date, Butler 677; and C. Kelseyi three days later a little 
higher up in the mountains, Butler 308. 
Carpuus EATONI XOLIVESCENS 
Cnicus Eatont A. Gray included several forms. Three of 
these had been distinguished by D. C. Eaton, who, however, had 
applied wrong names for two of them. The first of the three 
Eatonian synonyms cited by Dr. Gray is Cirsium eriocephalum 
var. leiocephalum. Dr. Gray’s description also applies principally 
tothis. Hence Carduus leiocephalus (D.C. Eaton) Heller becomes 
asynonym. Cirsium foliosum D.C. Eaton, I think, is the same — 
as Carduus nevadensis Greene and C. Drummondi D. C. Eaton is 
a Nevada plant, almost identical with C. oreophilus of Colorado. 
The supposed hybrid under consideration resembles C. Eaton 
in general habit, but the leaves have fewer and deeper lobes and 
are grayish tomentose beneath, and the involucres have shorter 
and weaker spines. It differs from C. olivescens in the broader 
segments of the leaves, the narrower bracts, of which the outer are 
spinulose-ciliate as in C. Eatont. 
Uran: Aquarius Plateau, Aug. 4, 1905, Rydberg & Carlton 7422. 
Carduus olivescens also grew on the Aquarius Plateau. The 
type of it was collected the following day and bears the’ number 
7450. C. Eatoniis common in the same region, although Carlton 
and myself did not preserve any specimens from the Aquarius 
Plateau. 
CARDUUS PULCHELLUS X UNDULATUS 
This most resembles Carduus pulchellus in habit, but the in- 
volucres are more hemispheric instead of truly campanulate, the 
bracts are broader and with a narrow glutinous ridge, and the inner 
