45 



Yellowstone. Varies in height from a few inches to three feet, ac- 

 cording to locality. 



55. [Crataegus coccinea Linn.] Occasional along the banks 

 of the streams. 



56. Amelanehier Canadensis T. and G. Heart River 

 Crossing, June 25th. Widely dispersed, but not common anywhere. 



ONAGRACE^. 



57. Epilobium paniculatum Nutt. Bad Route Creek, 

 July 28 th. 



58. Gaura coccinea Nutt. Heart River, July 6,th. 



59. CEaothera biennis Linn. Bad Route Creek, July 28th. 

 59a. CHnothera biennis Linn., var. Head of Heart River, 



July 8 th. 



60. Oenothera albicaulis Nutt. Head of Heart River, July 

 28 th. 



61. GEnothera serrulata Nutt. Second Crossing of Heart 

 River, July 6th. 



62. (Enothera pinnatifida Nutt. Great Bend of Heart 

 River, June 23d. 



63. (Enothera csespitosa Nutt. Near Fort Rice, June 20th. 



LOASACEiE. 



64. Mentzelia nuda Linn. Shell Point, Yellowstone River, 

 July lfith. 



CACTACE^. 



65. [Opuntia Missouriense D. C] Common at Fort Rice, 

 and increasing in abundance westward. In the Yellowstone Valley, 

 and between the Yellowstone and Musselshell Rivers it often nearly 

 covers the ground for large distances. 



66. [Opuntia fragilis Nutt.] More or less common on the 

 prairies west of Fort R : ce, but increases in abundance westward, in 

 places nearly covering the ground, and though smaller, is far more 

 troublesome to animals in traveling than the preceding species. 



67. [Mamillaria vivipara Nutt.] Common throughout the 

 region traversed. 



