43 



VITACEiE. 



19. Vitis cordifolia Michx. Heart River, June 24th. Also 

 on the Yellowstone, a short distance below Pompey's Pillar. 



20. Aaapelopsis quinquefolia Michx. Heart River, June 

 24th. 



CELASTRACE^]. 



21. Celastrus scandens L. Heart River, June 24th. 



ACERACE^J. 



22. Negundo aceroides Maench. One of the most common 

 trees along all the streams from the Missouri to the Musselshell. 

 This and the cottonwood (Populus monulifera) constitute the only- 

 trees met with at many localities. 



POLGALACE^. 



23. Poly gala alba Nutt. Common on the moister prairies, 

 from Fort Rice westward. 



LEGUMINOS^. 



24. Lupinus pusillus Pursh. Common on the prairies be- 

 tween the Missouri and Little Missouri Rivers. 



25. Psoralea floribunda Nutt. Yellowstone Valley, at mouth 

 of Little Porcupine Creek, August 7th. 



26. Psoralea lanceolata Pursh. Moist bottom-land of the 

 Missouri, at Fort Rice, June 15th. 



27. Psoralea argophylla Pursh. Great Bend of Heart 

 River, July 24th. 



28. Psoralea esculenta Pursh. Near Fort Rice, June 20th. 



29. Hosackia Purshiana Benth. Prairies west of Little 

 Missouri, July 11th. 



30. Petalostemon Candida Michx. Common on the prai- 

 ries from the Missouri to the Yellowstone. 



31. Petalostemon violaeeum Michx. With the preceding, 

 and equally common. 



32. Lathyrus ochroleucus Hook. Fort Rice, June 15th. 



33. Lathyrus linearis Nutt. Bottom-lands of the Missouri 

 at Fort Rice, June 15th. Abundant. 



34. Vieia Americana Muhl. Fort Rice, June 16th. Common. 

 34a. Vicia Americana Muhl., var. Valley of the Little Mis- 

 souri, at mouth of Davis Creek, July 10th. 



35. Astragalus lotiflorus Hook. Near Heart River, Jaly 7th. 



