Part 2, 1920] FABACEAE: PSORALEAE 119 



6. Thornbera Ordiae (A. Gray) Rydberg. 



Dalea albiflora var. A. Gray. PI. Wright. 2: 38. 1853. 

 Dalea Ordiae A. Gray, Proc. Am. Acad. 17: 200. 1882. 

 Parosela Ordiae A. Heller. Cat. N. Am. PI. ed. 2. 6. 1900. 



A perennial, somewhat woody at the base; stems 3-5 dm. high, finely pubescent; leaves 

 2-4 cm. long, ascending; stipules filiform, 2-3 mm. long; rachis finely pubescent, sparingly 

 glandular-punctate; stipels gland-like; leaflets 21-33, linear, more or less involute, 3-4 mm. 

 long, sparingly pubescent, glandular-punctate beneath; peduncles 1-4 cm. long; spikes dense, 

 2-7 cm. long, 7-8 mm. thick; bracts lanceolate, acuminate, shorter than the calyx; calyx- 

 tube campanulate, sharply 10-ribbed, densely pilose, with a row of glands between the ribs, 

 2.5 mm. long; lobes subulate, 1-1.5 mm. long; corolla white; petals like those of D. albiflora; 

 pod densely villous and glandular-dotted above, glabrate below. 



Type locality: Plains near Bovie and Rucker Valley, southern Arizona. 

 Distribution: New Mexico, Arizona, Chihuahua, and Sonora. 



7. Thornbera Grayi (Vail) Rydberg. 



Dalea laevigata A. Gray. PI. Wright. 2: 38. 1853. Not D. laevigata Moc. & Sesse, 1832. 

 Parosela Grayi Vail, Bull. Torrey Club 24: 14. 1897. 



A perennial herb, with a woody caudex; stems several, erect, striate, glabrous; leaves 2-4 

 cm. long, ascending; stipules subulate, 1-2 mm. long; petioles 3-5 mm. long; rachis glabrous, 

 slightly glandular-dotted; stipels wanting; leaflets 35-41, oblong to oval, mucronate, 2-4 mm. 

 long, glabrous, glandular-dotted beneath only; peduncles terminating the stems and branches, 

 1-5 cm. long; spikes dense, 1-3 cm. long, 8 mm. thick; bracts ovate, acuminate, sparingly 

 glandular-dotted, villous-pilose, subpersistent; calyx-tube 2 mm. long, villous, 10-ribbed, 

 inconspicuously glandular-punctate; lobes deltoid-ovate, acuminate, nearly equaling the tube; 

 corolla white or cream-colored; blade of the banner rounded-ovate, 2 mm. long, the claw 3 

 mm. long; blades of the other petals distinct, oblong, 2.5 mm. long, the claws very short; pod 

 pubescent and minutely glandular-dotted above, glabrate below. 



Type locality: Chiricahui Mountains, Sonora. 



Distribution: New Mexico and Arizona to Sonora and Durango. 



S. Thornbera revoluta (S. Wats.) Rydberg. 



Dalea revoluta S. Wats. Proc. Am. Acad. 22: 404. 1887. 

 Parosela revoluta Rose, Contr. U. S. Nat. Herb. 10: 105. 1906. 



A perennial, with a woody root and a short cespitose caudex; stems 3-6 dm. high, glabrous, 

 angled, glandular-dotted; leaves 1-3 cm. long, spreading; stipules filiform, 3 mm. long; rachis 

 glabrous, copiously glandular-dotted; leaflets about 21, linear, revolute, glabrous, densely 

 glandular-dotted, 4—10 mm. long; peduncles 3-8 cm. long; spikes dense, 1.5-4 cm. long, 6-7 

 mm. thick; bracts ovate, acuminate, puberulent, densely punctate, persistent, ciliate at the 

 base; calyx-tube campanulate, 10-ribbed, densely short-pilose, with a row of glands in the 

 intervals, 2 mm. long; lobes lanceolate, 1 mm. long, pilose; corolla white or the banner tinged 

 with rose; blade of the banner round-ovate, truncate at the base, 2 mm. long, the claw 2.5 mm. 

 long; blades of the other petals obliquely oblong, cuneate at the base on the lower and rounded 

 on the upper edge, 2 mm. long, the claws 0.5 mm. long; pod densely pubescent. 



Type locality: Guadalajara, Jalisco. 



Distribution: Sonora to Jalisco. 



9. Thornbera Pringlei (A. Gray) Rydberg. 



Dalea Pringlei A. Gray, Proc. Am. Acad. 17: 201. 1882. 

 Parosela Pringlei A. Heller, Cat. N. Am. PI. ed. 2. 6. 1900. 



A perennial, suffrutescent at the base, 3-6 dm. high, glabrous and glaucous, almost gland- 

 less; leaves 4-6 cm. long, ascending; stipules subulate, 1-2 mm. long; rachis glabrous and 

 glandless, except the minute gland-like stipels; leaflets 19-47, oblong, 2-5 mm. long, obtuse 

 or acutish, glabrous on both sides, finely glandular-dotted beneath; peduncles 3-10 cm. long; 

 spikes 3-10 long, 7-8 mm. thick; bracts ovate, acuminate, rather persistent, dark, pilose and 

 glandular-dotted, slightly exceeding the calyx; calyx-tube campanulate, 2 mm. long, pilose, 



