Genus 25. 



PEA FAMILY. 



I. Geoprumnon crassicarpum (Nutt.) 

 Rydb. Ground i'lum. Fig. 2530. 



Astragalus crassicarpus Nutt. Eraser's Cat. 1813. 

 Astragalus carnosus Pursh. Fl. Am. Sept. 740. In 



part. 181 4. 

 A. caryocarpus Ker. Bot. Reg. 2: pi. 176. 1S16. 

 G. crassicarpum Rydb. in Small, Fl. SE. U. S. 616. 



1903- 



.Oppressed-pubescent, branching at the base, 

 branches decumlient or ascending, 6'-i5^'^ long, 

 mostly simple. Stipules ovate, acute, 2"-3" long; 

 leaflets 15-25, oblong, elliptic or sometimes obo- 

 vate, obtuse, narrowed at the base, ,^"-6" long, 

 lY'-zi" wide; peduncles equalling or shorter than 

 the leaves ; flowers violet-purple, 8"-9" long, in 

 short racemes ; pods thick, glabrous, globose or 

 oval, short-pointed, 8"-i2" in diameter. 



Prairies, Minnesota to Manitoba, Saskatchewan, 

 Iowa, Missouri, Colorado and Texas. Fruit edible, 

 collected by prairie-dogs for their winter store. April- 

 June. Buffalo-pea, -bean or -apple. 



3. Geoprumnon plattense (Nutt.) Rydb. 

 Platte Milk Vetch. Fig. 2532. 



Astragalus plattensis Nutt. ; T. & G. Fl. N. A. I : 



332. 1838. 

 G. plattense Rydb. in Small, Fl. SE. U. S. 616. 1903. 



Villous-pubescent with spreading hairs, pros- 

 trate or ascending, 6'-i2' high or long. Leaflets 

 13-29, oblong to obovate, obtuse at the apex, nar- 

 rowed at the base. a"-9" long, about 2" wide ; 

 stipules broad, ovate, pointed, 3"-4" long; flowers 

 yellowish-white or tipped with purple, about 9" 

 long, in short heads : pod ovoid, pointed, .smooth, 

 loosely pubescent, nearly straight. 



Prairies, Indiana to Minnesota and Nebraska, 

 south to Alabama and Texas. May. 



2. Geoprumnon mexicanum (A. 



DC.) I'iydb. Larger Ground 

 Plum. Fig. 2531. 



Astragalus mexicanus A. DC. Fl. Rar. Jard. 



Gen. 4:16. 1826. 

 Astragalus trichocalyx Nutt. ; T. & G. Fl. N. 



A. 1:332. 1838. 

 G. mexicanum Rydb. in Small, Fl. SE. U. S. 



616. 1903. 



Similar to the preceding species, but 

 less pubescent and with the hairs some- 

 what spreading. Leaflets 17-33, oblong 

 to obovate, obtuse or emarginrt' at the 

 apex, narrowed at the base ; flowers yel- 

 lowish-white, or purplish at the tip. 9"- 

 12" long, in short racemes ; pod thick, 

 glabrous, globose, not pointed, I'-i 1' in 

 diameter. 



Prairies, Illinois to Nebraska, Kansas. 

 Louisiana and Texas. Fruit edible. May. 



