196 
ON THE GEOLOGY AND NATURAL HISTORY 
Solidago rigida, Linn. Bellevue to the Yellowstone. 
Solidago incana, Torr. and Gray. Fort Pierre to Yellowstone. 
Solidago Missouriensis, Nutt. Bellevue to Fort Pierre. 
Solidago gigantea, Ait. Common along the Missouri and Yellowstone. 
Solidago speciosa, Nutt. Black hills, September 3d. 
Grindelia squarrosa, Dunal. Common on high prairies from latitude 43° to the 
mountains ; medicinal among Indians. 
Chrysopsis villosa, Nutt. Common on dry hills, Fort Pierre. 
Chrysopsis hispida, Hook. Bad Lands and Yellowstone. 
Diaperia prolifera, Nutt. Common on Yellowstone. 
Silphium laciniatum, Linn. Called by the inhabitants of the country, ‘“‘ Compass 
plant ;” reaches its healthiest growth on the rich fertile bottoms of Missouri, but 
often found in great abundance on the high prairies. The highest point on the 
Missouri river that I have observed this plant, is near latitude 44°, mouth of 
White river; most abundant in the Platte valley, and on the broad rich bottoms 
between Council bluffs and Niobrara river, where it sometimes occupies large 
areas to the exclusion of other vegetation. That the leaves of this plant set 
their edges north and south, may be proved by a pocket compass. Forty-nine 
plants out of fifty exhibit this peculiarity. It thus becomes an excellent guide 
to the traveller across the pathless prairies. 
Silphium integrifolium, Michx. Belleyue, N. T. 
Silphium perfoliatum, Linn. Seldom seen above the mouth of Niobrara river. 
| Euphrosyne xanthifolia, Gray. Yellowstone and Upper Missouri in bottoms ; a green 
and canescent form. 
Iva axillaris, Pursh. Dry argillaceous hills. Fort Pierre and Fort Union. 
Ambrosia trifida, Linn. Along streams and borders of woods, from mouth of Mis- 
souri to mountains. Quite abundant. 
Ambrosia coronopifolia, Torr. and Gray, Fort Pierre. 
Franseria Hookeriana, Nutt. Sandy bottoms of Yellowstone river. 
Heliopsis laevis, Pers. Along streams in Kansas and Nebraska to Fort Pierre. 
Xanthium strumarium, Linn. Sandy bottoms of Yellowstone. 
Echinacea purpurea, Moench. Purple cone flower, called Rattlesnake Weed in the 
West, and is found abundantly throughout the country. Root very pungent. 
Used very effectively by the traders and Indians for the cure of the bite of the 
rattlesnake. 
Echinacea angustifolia, D.C. Fort Pierre, Bad Lands, Yellowstone. Mostly very 
hispid ; hoary. 
