362 NORTH AMERICAN FLORA [Volume 24 



wings about 4 mm. long, the blade obliquely obovate, with a large basal auricle; keel-petals 

 still shorter, similar but the blade broader, more arcuate, rounded at the apex; pod ellipsoid, 

 7-9 mm. long, about 4 mm. wide, glabrous, tapering below into a minute stipe; seeds obliquely 

 round-reniform. 



Type locality: Sierra Madre, Chihuahua. 



Distribution: Chihuahua. 



Illustration: M. E. Jones, Rev. Astrag. pi. 11. f. 50. 



22. Preussianae. Stout perennials, only slightly hairy. Calyx-tube cylindro-campanu- 

 late, longer than the short teeth. Corolla purplish, rather large, the banner elongate and 

 slightly arcuate. Pod stipitate, but the stipe often short, the body inflated, rather firm, 

 ellipsoid, 2-valved at the apex, rounded in cross-section. 



93. Phaca ampullaria (S. Wats.) Rydb. Bull. Torrey Club 

 40:47. 1913. 



Astragalus ampullarius S. Wats. Am. Nat. 7: 300. 1873. 

 Tragacantha ampullaria Kuntze, Rev. Gen. 943. 1891. 



Perennial; stem 1-2 dm. high, sparingly strigose; leaves about 5 cm. long, spreading; 

 stipules lanceolate or ovate, 5-7 mm. long, membranous; leaflets 7-11, obovate, rounded or 

 retuse at the apex, 6-10 mm. long, 4—7 mm. wide, cuneate at the base, glabrous above, sparingly 

 strigulose beneath; peduncles 2-5 cm. long; racemes headlike, 8-12-flowered; bracts lanceolate, 

 2-3 mm. long; pedicels 1-2 mm. long; calyx strigulose with black hairs, the tube 5-6 mm. long, 

 2-3 mm. wide, the teeth deltoid, 1 mm. long; corolla purple, 17-18 mm. long; banner obovate, 

 notched at the apex; wings 15-16 mm. long, the blade lanceolate, with a large reflexed auricle; 

 keel-petals much shorter, the blade broadly lunate; pod glabrous, long-stipitate, the stipe 1.5-2 

 cm. long, the body ovoid, 1.5-2 cm. long, 10-12 mm. wide. 



Type locality: Kanab, Utah. 

 Distribution: Southern Utah. 

 Illustration: M. E. Jones, Rev. Astrag. pi. 33, /. 114. 



94. Phaca Preussii (A. Gray) Rydb. Bull. Torrey Club 

 40:47. 1913. 



Astragalus Preussii A. Gray, Proc. Am. Acad. 6: 222. 1864 

 Tragacantha Preussii Kuntze. Rev. Gen. 947. 1891. 

 Rydbergiella Preussii Rydb. Fl. Rocky Mts. 501. 1917. 



Perennial, with a woody taproot and a short cespitose caudex; stems several, 2-5 dm. high, 

 sulcate, glabrous, stout; leaves 7-11 cm. long, spreading; stipules large, free, broadly deltoid, 

 5-7 cm. long; leaflets 11-15, oblong to broadly obovate, 8-18 mm. long, glabrous, obtuse to 

 emarginate at the apex, somewhat fleshy; peduncles ascending, 5-10 cm. long, sulcate, glabrous; 

 racemes 4—6 cm. long; bracts lanceolate, about 2 mm. long, equaling the pedicels; flowers 

 spreading; calyx glabrous, cylindric, the tube about 7-8 mm. long, the teeth subulate, 2-2.5 

 mm. long; corolla purple, about 2 cm. long; banner obovate, slightly arched, emarginate at the 

 apex; wings much shorter, the blade oblong, shorter than the claw, with a large reflexed auricle; 

 keel-petals about as long and similar, slightly broader and more lunate; pod glabrous, stipitate, 

 the stipe 5-8 mm. long, the body oblong-ellipsoid, 2-3 cm. long, about 1 cm. wide and thick; 

 seeds obliquely reniform, 4 mm. long, 2.5 mm. broad. 



Type locality: Banks of Rio Virgin |Nevada|. 



Distribution: Central Utah to southeastern California and central Arizona. 



Illustration: M. E. Jones, Rev. Astrag. pi. 32, f. 113. 



95. Phaca Davidsonii Rydberg, sp. now 



Perennial; stems several from a woody root and short caudex, sulcate, glabrous, 2-4 dm. 

 high; leaves 5-10 cm. long, ascending; stipules broadly deltoid, 3-5 mm. long, scarious, the 

 lower very broad; leaflets 11-15, broadly obovate, 6-20 mm. long, 4-10 mm. wide, glabrous, 

 usually retuse or obcordate at the apex; peduncles 6-12 cm. long; racemes rather lax, 4-8 cm. 



