22 NORTH AMERICAN FLORA [Volume 24 



12. Pediomelum megalanthum (Wooton & Standley) Rydberg. 



Psoralea mephilica Rydb. Fl. Colo. 214. 1906. Not P. mephilica S. Wats. 1879. 

 Psoralen megalantha Wooton & Standley, Contr. U. S. Nat. Herb. 16: 140. 1913. 



A low perennial, with a tuberous root; stem above ground very short; leaves digitately 

 5-6-foliolate, clustered at the base; stipules scarious, ovate, about 1 cm. long; petioles 4—8 

 cm. long, densely white-strigose; leaflets obovate, 1-3 cm. long, densely white-strigose beneath, 

 less densely so above; peduncles stout, 1-4 cm. long, white-strigose and with a few spreading 

 hairs; spikes about 2 cm. long, dense; bracts lanceolate or ovate-lanceolate, about 1 cm. long, 

 acute; pedicels 1-3 mm. long; calyx campanulate; tube 5-6 mm. long; lobes about 1 cm. long, 

 all subulate; corol'a 2 cm. long or nearly so; banner oblong. 



Type locality: Aztec, New Mexico. 



Distribution: Western Colorado, eastern Utah, and northern New Mexico. 



13. Pediomelum mephiticum (S. Wats.) Rydberg. 



Psoralea mephilica S. Wats. (; E. Palmer, Am. Nat. 12: 601; hyponym. 1878) Proc. Am. Acad. 14: 

 291. 1879. 



A perennial, with a fusiform root about 1 dm. long and 1 cm. thick; stem above ground 

 scarcely any; leaves clustered at the base, digitately 5-foliolate; stipules scarious, ovate, acu- 

 minate, 1 cm. long or less; petioles 4-6 cm. long, with spreading orretrorse pubescence; leaflets 

 cuneate or obovate, rounded or retuse at the apex, 1-2 cm. long, canescently strigose beneath, 

 less densely so or glabrate above; peduncles 2-5 cm. long, with spreading or reflexed white 

 hairs; spikes about 2 cm. long, dense; bracts ovate, scarious, acuminate or acute; calyx long- 

 hairy; tube 4 mm. long; lobes subequal in length, 7-8 mm. long, the upper four subulate, the 

 lowest one lanceolate; corolla blue, about 12 mm. long; banner oblong. 



Type locality: Near Beaver City, Utah [as given by Watson; Palmer, loc. cit., gives the locality 

 southeast of St. George, Utah]. 



Distribution: Southern Utah and Arizona. 



14. Pediomelum retrorsum Rydberg, sp. nov. 



A perennial, with a fusiform root about 2 cm. thick; stem very short, usually with a few 

 decumbent stout branches, 1-2 dm. long, densely canescent with long re trorse hairs; leaves 

 digitately 5-foliolate; stipules ovate, 1-1.5 cm. long, densely hairy; petioles 3-12 cm. long, 

 retrorsely hairy; leaflets rounded-obovate, 2-4 cm. long, densely silky-canescent with appressed 

 hairs, the veins prominent on the upper side; peduncles of the main stem 5-7 cm. long, those 

 of the branches often very short, only 1-2 cm. long, densely retrorse-hairy ; spikes 3-7 cm. long; 

 bracts lanceolate, acuminate; pedicels 1-2 mm. long or less; calyx silky-hirsute; tube 5 mm. long; 

 lobes about 7 mm. long, the upper 4 subulate, the lowest one linear-lanceolate; corolla about 

 17 mm. long; banner obovate, with rounded basal lobes. 



Type collected at Peach Spring near Big Bend of the Colorado, Arizona, June, 1884, /. G. Lem- 

 rnon &> wife (herb. Columbia Univ.). 



Distribution: Type locality and vicinity. 



15. Pediomelum castoreum (S. Wats.) Rydberg. 



Psoralea castorea S. Wats. (; E. Palmer, Am. Nat. 12: 601; hyponym. 1878) Proc. Am. Acad. 14: 



291. 1879. 

 Lolodes castoreum Kuntze, Rev. Gen. 194. 1891. 



A perennial, with a fusiform, farinaceous, tuberous root 5-8 cm. long, 1-3 cm. thick; 

 stem very short, less than 1 dm. high, strigose-canescent, sometimes with decumbent branches 

 1 dm. long or more; leaves digitately 3-5-foliolate; stipules membranous, ovate, acute, 1 cm. 

 long; petioles 5-10 cm. long; leaflets cuneate-obovate, rounded, acute, or even retuse at the 

 apex, strigose-canescent beneath, sparingly strigose above, 2-4 cm. long; peduncles 3-5 cm. 

 long; spikes dense, 2-4 cm. long; bracts ovate, lanceolate, or oblong, acute or obtuse, 5 mm. 

 long or less; calyx canescent-strigose; tube 2 mm. long; upper four lobes subulate, attenuate, 

 7-8 mm. long, the lowest one spatulate or obovate, rounded or obtuse at the apex, about 10 

 mm. long; corolla blue, fully 1 cm. long; banner oblong; body of the pod ovoid, 8 mm. long, the 





