348 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



10. ACMISPON Raf. 



Annual, similar to Aniso lotus; leaves 3-foliolate, rarely 1-foliolate; stipules reduced 

 to mere traces of glands; pod straight, readily dehiscent. 



1. Acmispon americanum (Nutt.) Rydb. Bull. Torrey Club 40: 45. 1913. 



Lotus sericeus Pursh, Fl. Amer. Sept. 489. 1814, not DC. 1813. 



Trigonella ainericana Nutt. Gen. PI. 2: 120. 1818. 



Type locality: " On the dry and open alluvial soils of the Missouri, from the river 

 Platte to the Mountains." 



Range: Washington and Minnesota to California and New Mexico. 



New Mexico: Mule Creek (Wooton). 



11. PSORALEA L. 



Perennial, more or less gland-dotted herbs (glands inconspicuous in some species) , 

 with palmately 3 to 5-foliolate leaves; flowers in capitate or racemose clusters; sta- 

 mens diadelphous; pods small, 1-seeded, indehiscent. 



KEY TO THE SPECIES. 



Flowers more than 12 mm. long, in dense spikes; plants low, with 

 short stems; roots long, tuberous. 



Stems hirsute 6. P. esculenta. 



Stems not hirsute, the pubescence sericeous or canescent. 



Leaflets linear to oblanceolate, acutish; spikes elongate. . . 1. P. hypogaea. 



Leaflets obovate, rounded; inflorescence subcapitate 2. P. megalantha. 



Flowers small, less than 8 mm. long, in racemes or interrupted 

 spikes; plants tall and branching; roots not tuberous. 



Flowers in interrupted spikes; leaves silvery 3. P. argophylla. 



Flowers in racemes; leaves not silvery. 



Racemes short and dense; fruit globose; upper leaflets 



linear 4. P. micrantha. 



Racemes loose, elongate; fruit ovoid; upper leaflets ob- 

 lanceolate or elliptic 5. P. tenuiflora. 



1. Psoralea hypogaea Nutt.; Torr. & Gray, Fl. N. Amer. 1: 302. 1838. 

 Type locality: "Plains of the Platte." 



Range: Nebraska to New Mexico and Texas. 

 New Mexico: Taos (Stevenson). 



2. Psoralea megalantha Woot. & Standi. Contr. TJ. S. Nat. Herb. 16: 140. 1913. 

 Type locality: Aztec, New Mexico. Type collected by Baker (no. 440). 

 Range: Known only from type locality, in the Upper Sonoran Zone. 



3. Psoralea argophylla Pursh, Fl. Amer. Sept. 475. 1814. 

 Type locality: "On the banks of the Missouri." 



Range: Wisconsin and Saskatchewan to Missouri and New Mexico. 

 New Mexico: Sierra Grande; Raton Mountains. Open slopes. 



4. Psoralea micrantha A. Gray, U. S. Rep. Expl. Miss. Pacif. 4: 77. 1856. 

 Type locality: "Sand hills, near the last camp on the upper Canadian." 

 Range: Oklahoma and western Texas to Arizona. 



New Mexico: West of Santa Fe; Coolidge; Tesuque; San Augustine Plains; Zuni; 

 Mogollon Mountains. Upper Sonoran Zone. 



