Part 1, 1919] FABACEAE: PSORALEAE 15 



those of the branches 1-foliolate; stipules lanceolate or subulate, 3-7 mm. long; petioles 1-5 

 mm. long; leaflets linear, 2-6 cm. long, 1-3 mm. wide, with numerous small glands, glabrous 

 above, sparingly strigose beneath, acute at both ends; peduncles 4-8 cm. long; racemes lax, 

 few-flowered, 3-6 cm. long; flowers 1-4 at each node; bracts lanceolate, acuminate; pedicels 

 4-8 mm. long; calyx 3-4 mm. long, conspicuously punctate, sparingly strigose; lobes lanceo- 

 late, acute, as long as the tube; corolla blue, 7-8 mm. long; banner rounded-obovate ; pod 8 

 mm. long, ovoid, flattened, gradually tapering into a straight beak; seed dark-brown, broadly 

 obliquely reniform. 



Type locality: Arkansas. 



Distribution: Western Nebraska and eastern Wyoming to Arkansas and Texas 



Illustrations: Britt. & Brown, 111. Fl./. 2091; ed. 2./. 2494. 



7. Psoralidium tenuiflorum (Pursh) Rydberg. 



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

 Lotodes tenuiflorum Kuntze, Rev. Gen. 194. 1891. ' 



A perennial, with a long rootstock; stem 2-6 dm. high, more or less strigose, glandular- 

 dotted, much branched; leaves digitately 3-foliolate or the lower rarely 5-foliolate; stipules 

 lanceolate, 2-3 mm. long, deciduous; petioles 3-12 mm. long; leaflets 1-4 cm. long, 5-8 mm. 

 wide, oblong-oblanceolate, obtuse, mucronate, glandular-dotted on both sides, glabrate above, 

 strigose beneath; peduncles 2-4 cm. long; racemes 1.5-4 cm. long; bracts minute, ovate or 

 lanceolate, acuminate; flowers solitary or two at each node; pedicels 2-4 mm. long; calyx 

 2-2.5 mm. long, sparingly strigose, densely glandular-dotted; lobes nearly equal, lanceolate, 

 acute, nearly equaling the calyx-tube; corolla blue, about 5 mm. long; banner rounded-obovate] 

 nearly orbicular; pod ovoid, 7-8 mm. long, glabrous, densely glandular-dotted, with a short 

 straight beak; seed brown, kidney-shaped, shining. 



Type locality: Banks of the Missouri [Montana]. 

 Distribution: North Dakota and Montana to Texas and Arizona 

 28 f ll f USTRArioNS: Britt - & Brown, 111. Fl./. 2088; ed. 2. /. 24 92; Clements, Rocky Mt. Fl. pi. 



8. Psoralidium floribundum (Nutt.) Rydberg. 



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

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

 Psoralea tenuiflora floribunda Rydb. Fl. Neb. 21: 55. 1895. 



A perennial, with a horizontal rootstock; stem simple below, branched above, 5-12 dm. 

 high, canescent, strigose, not glandular-dotted; leaves digitately 5-foliolate or those of the 

 branches 3-foliolate; stipules 3-7 mm. long, subulate, deciduous; petioles 0.5-3 cm. long; 

 leaflets 1-5 cm. long, 3-10 mm. broad, elliptic to oblanceolate or linear, mucronate, glandular- 

 dotted on both sides, glabrous above, strigose beneath; peduncles 5-10 cm. long; racemes 

 4-10 cm. long, many-flowered; flowers 2-4 at each node; bracts lanceolate, acuminate; 

 calyx 3 mm. long, strigose-canescent ; lobes subequal, lanceolate, acute, as long as the corolla; 

 corolla 6-7 mm. long, blue or rarely white; banner suborbicular; pod ovoid, glabrous, densely 

 glandular-dotted, with a short erect beak, 8 mm. long; seed kidney-shaped, brown. 



Type locality: Plains of the Arkansas. 



Distribution: Illinois to Nebraska, Texas, and Arkansas 



Illustrations: Britt. & Brown, 111. Fl./. 2090; ed. 2./. 2493. 



9. Psoralidium Bigelovii Rydberg, sp. nov. 



Psoralea floribunda Torr. Bot. Mex. Bound. Surv. 51 (erroneously so referred) 18S9 



Psoralea obtusiloba Vail, Bull. Torrey Club 21 : 97, mainly. 1894. Not P. obtusiloba f. & G. 1838. 



A perennial, with a creeping rootstock; stem 3-6 dm. high, canescent, strigose, with more or 

 less spreading branches; leaves digitately 3-foliolate or the lower 5-foliolate; stipules subulate, 

 about 5 mm. long; petioles very short, 2-S mm. long; leaflets of the stem-leaves usually obovate| 

 1-3 cm. long, 5-12 mm. wide, with numerous small glands, glabrate above, strigose beneath, 

 retuse or obtuse and mucronate at the apex, those of the branches oblong or oblanceolate! 

 smaller; peduncles 4-7 cm. long; racemes 3-5 cm. long, interrupted, many-flowered; flowers 

 2 or 3 at each node; pedicels 1-2 mm. long; calyx about 3 mm. long, sparingly long-strigose ; 

 upper four lobes lanceolate, fully as long as the tube, the lower one subulate, slightly longer; 



