STANDLEY TKEES AND SHRUBS OF MEXICO. 451 



In dry soil, San Luis Potosi and Aguascalientes to Oaxaca ; type from Villar, 

 San Luis Potosi. 



Plants very slender, 20 to 60 cm. high," with a thick woody root ; stems, glab- 

 rous ; leaflets 17 to 37, oval or suborbicular, 1 to 2 mm. long, glabrous ; racemes 

 5 to 10 cm. long, remotely flowered ; calyx villous ; petals yellowish below, pur- 

 plish above. 



2. Parosela berlandieri (A. Gray) Rose, Contr. U. S. Nat. Herb. 10: 106. 1906. 

 Dalea berlandieri A. Gray, Proc. Amer. Acad. 5 : 177. 1861. 



San Luis Potosi and Tamaulipas ; type from San Carlos, Tamaulipas. 



Slender shrub, 0.5 to 1 meter high ; branches glabrous ; leaflets 5 or 7, cuneate 

 or obovate-oblong, 3 to 4 mm. long, glabrous; racemes lax, 2 to 4 cm. long; 

 calyx densely pilose ; petals at first yellowish, becoming reddish ; fruit pilose. 



3. Parosela sericocalyx Rydb. N. Amer. Fl. 24: 63. 1919. 



Known only from the type collection, from the Sierra Madre of Durango or 

 Sinaloa. 



Slender shrub, 50 cm. high or more ; stems silky-villous when young ; leaflets 

 9 to 21, oval, sericeous on both sides, 10 to 15 mm. long; racemes 2 to 4 cm. 

 long ; calyx sericeous ; petals reddish purple ; fruit sericeous. 



4. Parosela calycosa (A. Gray) Heller, Cat. N. Amer. PI. ed. 2. 5. 1900. 

 Dalea calycosa A. Gray, PI. Wright. 2: 40. 1853. 



Chihuahua, Sonora, and Nuevo Le6n ; tyi")e collected on the San Pedro, 

 Sonora. New Mexico and Arizona. 



Plants suffrutescent, 10 to 30 cm. high or more ; stems slender, strigose- 

 canescent ; leaflets 15 to 29, oval or obovate, 3 to 5 mm. long, obtuse or retuse, 

 glabrous above, strigose beneath ; racemes 2 to 4 cm. long, dense ; calyx densely 

 pilose ; petals white and purple ; fruit pilose. 



5. Parosela orcuttii (S. Wats.) Parish, Bot. Gaz. 55: 305. 1913. 

 Dalea orcuttii S. Wats. Proc. Amer. Acad. 20: 359. 1885. 



Northern Baja California ; type from Topo and Cantillas Canyon. Southern 

 California. 



Stems suffrutescent, ascending, 10 to 20 cm. long, strigose-canescent ; leaflets 

 9 to 17, oblong-obovate, 2 to 4 mm. long, glabrous above, strigose beneath ; 

 racemes 1 to 2 cm. long, dense; calyx hirsute-pilose; petals purple and whitish. 



6. Parosela spinosa (A. Gray) Heller, Cat. N. Amer. PI. ed. 2. 7. 1900. 

 Dalea spinosa A. Gray, Mem. Amer. Acad. II. 5: 315. 1854. 



Dalea spinescens Hemsl. Biol. Centr. Amer. Bot. 1: 247. 1880. 



Psorodendron spinosum Rydb. N. Amer. Fl. 24: 45. 1919. 



Sonora and Baja California. Arizona and southern California ; type from 

 the Gila River. Arizona. 



Densely branched shrub or small tree, 4 to 7 meters high ; leaves 2 to 5 cm. 

 long, irregularly dentate, early deciduous ; recemes 3 to 5 cm. long, the rachis 

 spinose ; calyx strigose ; petals dark blue ; fruit canescent ; wood soft, coarse- 

 grained, brown, its specific gravity about 0.55. "Mangle" (Sonora). 



The English name is " indigo-bush " or " indigo-thorn." The plant is very 

 showy when in flower. 



7. Parosela schottii (Torr.) Heller, Cat. N. Amer. PI. ed. 2. 6. 1900. 

 Dalea schottii Torr. U. S. & Mex. Bound. Bot. 53. 1859. 

 Psorodendron schottii Rydb. N. Amer. Fl. 24:44. 1919. 



Northern Baja California. Southern Arizona and California ; type from the 

 •Colorado River. 



