234 
IOWA ACADEMY OF SCIENCES. 
corolla tube ten one-half lines long, anther with very acute tips, 
achenium one and one-half lines long, pappus plumose. 
A specimen in the Engelmann Herbarium as well as 
several in the Gray Herbarium, are ticketed Cirsium canes - 
cens. 
In the Gray Herbarium is a specimen ticketed Cirsium 
undulatum B, Torrey and Gray, Flora of North America, 
( 2 : 456), collected by Mr. Charles A. Geyer, in August, 
1839, and labeled ‘‘Fertile prairies, near Devil's Lake, the 
only specimen found; please return it to Mr. Nicollet after 
examination.” There is a note by Dr. Gray: “Not 
improbably our C. undulatum var. /?.” 
Dr. Gray, in his revision of the genus Cnicus for the 
Synoptical Flora of North America (‘ : 403) says: 
Var. canescens , Gray, is merely a form with smaller heads, sometimes 
not over an inch high, leaves varying from cilialely-spinulose dentate 
to deeply pinnatitid. Cirsium canescens and C. brevifolium, Nutt. Trans. 
Am. Phil. Soc. 7: 421— Minnesota to Mexico and S. Utah. 
Another specimen is ticketed “ Cirsium hookerianum sas - 
katchawan , collected by Bourgeau, in 1858, in Palliser, Brit. 
N. A. Exp.” Another specimen of the Rocky Mountains, 
by Burt, in 1849; this was referred by Dr. Gray to C. undu- 
latus in the Syn. FI. N. A. ( 1 : 403). One specimen each in 
the Gray and Engelmann Herbarium, is ticked “ C. canes - 
cans , Nutt. Collected by Dr. Hayden on the Upper 
Platte.” This in the Gray Herbarium is placed under the 
variety canescens by Dr. Gray. Rydberg correctly consid- 
ered it as distinct, and referred his form to Carduus plat- 
tensis spinosior ; this specimen is clearly a form of Ryd- 
berg’s C. plattensis. 
The Fendler specimen, No. 73, collected near Fort 
Kearney, also belongs here. This species seems to be 
quite common in the Sand Hill region of Nebraska. This 
species and the Cnicus Nelsoni are closely allied to Cnicus 
Pitcheri. 
In the Gray Herbarium is a specimen marked “ Cnicus 
altissimus , Willd. var. filipendulus, Gray. Sandbars of Mis- 
souri river. Sioux City, Iowa, Hitchcock,” Dr. Sereno 
Watson having referred our Iowa material to the variety 
