16 NORTH AMERICAN FLORA [Volume 24 



corolla about 6 mm. long; banner orbicular; pod ovoid, flattened, copiously glandular-punc- 

 tate, 6-7 mm. long, with a short erect beak; seed brown, kidney-shaped. 



Tvpe collected at the Copper mines [Santa Rita del Cobre], New Mexico, 1850, Bigelow [Mex. 

 Bound. Surv.] 218 (herb. N. Y. Bot. Gard.). 



Distribution: Western Texas and southern Colorado to Arizona and Sonora. 

 Illustration: Britt. & Brown, 111. Fl. /. 2089 (as Psoralea obtusiloba). 



10. Psoralidium obtusilobum (T. & G.) Rydberg. 



Psoralea obtusiloba T. & G. Fl. N. Am. 1: 300. 1838. 

 Psoralea lenuiflora obtusiloba S. Wats. Bibl. Ind. 255. 1878. 



A perennial, with horizontal rootstock; stem 5-10 dm. high, sparingly strigose, with many 

 spreading branches; leaves digitately 3-5-foliolate; stipules subulate, very small; petioles 5-10 

 mm. long; leaflets obovate to oblanceolate, 1-4 cm. long, 5-10 mm. broad, with many small 

 glands, glabrate above, sparingly strigose beneath, rounded or obtuse, mucronate at the apex; 

 peduncles 2-4 cm. long; racemes 1-3 mm. long; flowers 1-3 at each node; pedicels about 2 

 mm. long; calyx 1.5 mm. long, sparingly strigose; lobes oblong, obtuse, shorter than the tube; 

 corolla about 4 mm. long, blue; banner orbicular; pod ovoid, flattened, with a short erect beak. 



Type locality: Texas. 



Distribution: Louisiana, Texas, and New Mexico. 



11. Psoralidium digitatum (Nutt.) Rydberg. 



Psoralea digitala Nutt.; T. & G. Fl. N. Am. 1: 300. 1838. 

 Psoralea campestris Nutt.; T. & G. Fl. N. Am. 1: 301. 1838. 

 Lotodes campestre Kuntze, Rev. Gen. 194. 1891. 

 Lotodes digitatum Kuntze, Rev. Gen. 194. 1891. 



A perennial, with a rootstock; stem erect, simple below, with ascending-spreading branches, 

 3-S dm. high, appressed-canescent throughout ; leaves mostly digitately 5-foliolate or those of 

 the branches 3-foliolate; stipules lanceolate, 5-10 mm. long; petioles 2-5 cm. long; leaflets 

 linear or linear-oblanceolate, 2-5 cm. long, 3-5 mm. broad, glabrous above except the midvein, 

 densely silky beneath ; peduncles 10-15 cm. long ; spikes interrupted, 3-6 cm. long ; bracts broadly 

 obovate, 5 mm. long, nearly as broad, sparingly glandular, abruptly short-acuminate; flowers 

 2-4 at each node, subsessile; calyx 6-7 mm. long, accrescent in fruit, densely silky; lobes ovate- 

 lanceolate, abruptly short-acuminate, the lowest somewhat longer; banner obovate; pod ovoid, 

 7-8 mm. long, with a flat straight beak; seed ellipsoid, brown, 4-5 mm. long. 



Type locality: Sandhills of Red River, Arkansas. 

 Distribution: South Dakota to Colorado, Texas, and Arkansas. 

 Illustrations: Britt. & Brown, 111. Fl. 2093; ed. 2./. 2496. 



12. Psoralidium collinum Rydberg. 



Psoralea collina Rydb. Fl. Neb. 21 : 54. 1895. 



A perennial, with a rootstock; stem ascending, diffusely branched, sparingly strigose and 

 glandular-punctate; leaves digitately 3-foliolate or the lower 5-foliolate; stipules lanceolate or 

 subulate, 2-8 mm. long; petioles 5-20 mm. long; leaflets obovate or oblanceolate, mucronate, 

 2-4 cm. long, glandular-punctate, glabrous or nearly so above, strigose beneath; peduncles 

 3-5 cm. long; spikes interrupted, lax, 3-5 cm. long; bracts lanceolate, pointed, 3-4 mm. long; 

 flowers 2-4 at each node, sessile; calyx 4 mm. long, strigose; lobes linear-lanceolate, longer than 

 the tube, the lowest only slightly longer; corolla blue, about 6 mm. long; banner broadly ob- 

 ovate; pod ovoid, 6-8 mm. long, tapering into a flat straight beak. 



Type locality: Pleasant Valley. Scott's Bluffs County, Nebraska. 



Distribution: Western Nebraska. 



Illustrations: Fl. Neb. 21: pi. 4,f. 6, 7; Britt. & Brown, 111. Fl./. 2092; ed. 2./. 2495. 



13. Psoralidium argophyllum (Pursh) Rydberg. 



Psoralea argophylla Pursh, Fl. Am. Sept. 475. 1814. 



Psoralea incana Nutt. (Fraser, Cat.; hyponym. 1813) Gen. 2: 102. 1818. 



Psoralea argophylla decumbens A. Gray. Pacif. R. R. Rep. 12 ! : 41. 1860. 



Lotodes argophyllum Kuntze, Rev. Gen. 194. 1891. 



Psoralea argophylla robustior Bates, Am. Bot. 20: 16. 1914. 



