Part 1, 1919] FABACEAE: PSORALEAE 45 



An intricately branched spinescent shrub, 1-3 m. high; branches slender, bright-green 

 and glabrate or sparingly and minutely strigose, nearly glandless; leaves linear, 0.5-3 cm. long, 

 1-2 mm. wide, sparingly puberulent, glandular-dotted along the margins; racemes 4-8 cm. long, 

 6-20-flowered; bracts and bractlets subulate, the former about 2 mm., the latter I mm. long; 

 pedicels 1-2 mm. long; calyx sparingly short-hirsute or soon glabrate, glandular-dotted; tube 

 turbinate, 3 mm. long; lobes ovate, 1.5-2 mm. long, acutish; corolla blue, the keel-petals slightly 

 longer than the rest; blade of the banner broadly obcordate, with small basal lobes, 6 mm. long, 

 those of the other petals obliquely obovate, with a round basal lobe, those of the wings 6 mm., 

 those of the keel-petals 7 mm. long the claws about 2 mm. long; pod obliquely ovate, conspicu- 

 ously glandular-dotted, the body about 1 cm. long, 6 mm. wide, the beak 5 mm. long. 



Type locality: Banks of the Colorado. 



Distribution: Southern California, western Arizona, and Lower California. 



Illustration: Bot. Gaz. 55: 311. /. 5. 



11. Psorodendron puberulum (Parish) Rydberg, sp. nov. 



Parosela Schottii pubenda Parish, Bot. Gaz. 55: 312. 1913. 



An intricately branched spinescent shrub; young branches densely canescent-puberulent, 

 in age glabrate and gray; leaves linear, 1-2.5 cm. long, 1-2 mm. wide, grayish-canescent when 

 young, glandular-dotted along the margins; racemes 3-5 cm. long; bracts and bractlets subu- 

 late, minute; pedicels less than 1 mm. long; calyx densely canescent, inconspicuously glandular- 

 dotted; tube 3 mm. long, elongate-turbinate, strongly 10-ribbed; lobes triangular, 1 mm. long; 

 corolla bluish-purple, about 10 mm. long; blade of the banner broadly obovate, emarginate, 

 6 mm. long, those of the wings and keel-petals oval, with a rounded basal lobe, 6 mm. long; 

 pod obliquely obovoid, puberulent and conspicuously glandular-dotted, the body nearly 1 

 cm. long, 5 mm. wide, the beak of nearly the same length. 



Type locality: Colorado Desert. 



Distribution: Colorado Desert, California, and northern Lower California. 



12. Psorodendron spinosum (A. Gray) Rydberg. 



Dalea spinosa A. Gray, Mem. Am. Acad. II. 5: 315. 1S54. 

 Asagraea spinosa Baillon, Adansonia 9: 233. 1870. 

 Dalea spinescens Hemsl. Biol. Centr. Am. Bot. 1: 247. 1S80. 

 Parosela spinosa A. Heller, Cat. N. Am. PI. ed. 2. 7. 1900. 



An intricately branched spinescent tree or shrub, 4—7 m. high; branches at first minutely 

 canescent, later becoming glabrous, yellowish-green, conspicuously glandular-dotted, the 

 glands at first conic; leaves simple, white-strigose, those of the young plant obovate, spatula te 

 or oblanceolate, irregularly dentate, 2-5 cm. long, those of the branches linear-oblanceolate, 

 5-15 mm. long, early deciduous; racemes 3-5 cm. long, spinescent; bracts and bractlets minute, 

 subulate; pedicels 1 mm. long or less; calyx densely white-strigose; tube turbinate, sharply 

 10-ribbed, with a solitary conspicuous gland in each interval, 3 mm. long; lobes ovate, acute, 

 1.5 mm. long; corolla dark-blue; blade of the banner broadly obcordate, 4 mm. long, those of 

 the wings obliquely oval, with a conspicuous basal lobe, 4-5 mm. long, those of the keel-petals 

 broader and with a more rounded basal lobe, about 6 mm. long, the claws of the wings and keel- 

 petals about 2 mm. long; pod obliquely ovate, canescent and glandular-dotted. 



Type locality: Arroyos of the Gila, Arizona. 



Distribution: Southern California, Arizona. Sonora. and Lower California. 

 Illustrations: Pacif. R. R. Rep. 7: pi. 3; Britton. N. Am. Trees /. 520; Sargent, Man. /. 471; 

 Sargent, Silva pi. Ill; Eastw. Handb. Trees Calif, pi. 39. 



15. PSOROTHAMNUS* Rydberg, gen. nov. 



Dalea § Xylodalea S. Wats. Proc. Am. Acad. 11: 132, in part. 1876. 



Intricately branched shrubs, with pinnate or simple deciduous leaves, and conspicuously 

 glandular-pustulate branches, the glands red or orange, turning brown. Flowers in dense, 

 short, often subglobose spikes; bracts lanceolate, caducous; bractlets wanting or represented 

 by glands. Calyx-tube turbinate, strongly 10-ribbed, with a row of glands in each interval. 



* From >pupa, scab, and da^vos, shrub. 



