370 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



20. OXYTROPIS DC. Loco weed. 



Like Astragalus in most particulars, but distinguished by the short subulate pro- 

 longation or beak of the keel. 



Several of the species are noxious loco weeds and do as much damage or more than 

 the species of Astragalus that pass under the same name. 



KEY TO THE SPECIES. 



Stipules free from the petiole ; pods pendulous 1 . 0. deflexa. 



Stipules adnate to the petiole; pods erect. 



Leaflets many, subverticillate; flowers purple 2. 0. richardsoni. 



Leaflets few, not verticillate; flowers purple to white. 



Flowers 1 to 3 ; plants 10 cm. high or less 3. 0. parryi. 



Flowers numerous; plants more than 10 cm. high. 



Flowers purple 4. 0. lambertii. 



Flowers white, the keel often spotted with purple. 

 Plants tall, 30 cm. or more; inflorescence elon- 

 gated 5. O. jrinetorum. 



Plants low, 15 cm. or less; inflorescence short and 



dense 6. 0. vegana. 



1. Oxytropis deflexa (Pall.) A. DC. Astrag. 96. 1802. 

 Astragalus dejkxus Pall. Act. Acad. Petrop. 3 2 : 268. pi. 15. 1779. 

 Aragallus dcflcxus Heller, Cat. N. Amer. PI. 4. 1898. 



Type locality: Southern Siberia. 



Range: British America to Utah and New Mexico. 



New Mexico: Rio Pueblo; Chama. Damp woods, in the Canadian Zone. 



2. Oxytropis richardsoni (Hook.) Woot. & Standi. 



Oxytropis splendens richardsoni Hook. Fl. Bor. Amer. 1: 148. 1833. 



Aragallus richardsoni Greene, Pittonia 4: 69. 1899. 



Type locality: "From Cumberland-House on the Saskatchewan, north to Fort- 

 Franklin and the Bear Lake, and west to the dry Prairies of the Rocky Mountains." 



Range: British America to northern New Mexico. 



New Mexico: Santa Fe and Las Vegas mountains; Costilla Valley. High moun- 

 tain meadows, in the Canadian Zone. 



A very handsome plant, occurring in great abundance in parks in the Santa Fe 

 and Las Vegas ranges. 



3. Oxytropis parryi A. Gray, Proc. Amer. Acad. 20: 4. 1885. 

 Aragallus parryi Greene, Pittouia 3: 212. 1897. 



Type locality: "Rocky Mountains of Northern New Mexico and Colorado, near 

 the limit of trees." 



Range: Colorado and northern New Mexico. 



New Mexico: Pecos Baldy (Bailey 616). High mountain meadows, in the Arctic- 

 Alpine Zone. 



4. Oyxtropis lambertii Pursh, Fl. Amer. Sept 740. 1814. 

 Aragallus lambertii Greene, Pittonia 3: 212. 1897. 



Aragallus metcalfei Greene, Proc. Biol. Soc. Washington 18: 12. 1905. 

 Type locality: "On the Missouri." 

 Range: British America to Arizona and Texas. 



New Mexico: Mountains and high plains nearly throughout the State. Meadows, 

 Upper Sonoran to Canadian Zone. 



