436 MISC. PUBLICATION 42 3, U. S. DEPT. OF AGRICULTURE 



15. Banner petal glabrous or nearly so; flowers 10 to 12 (rarely only 9) 

 mm. long (16). 

 16. Herbage, including the upper surface of the leaflets, densely 



sericeous; southern 15. L. lemmonii. 



16. Herbage green, the pubescence sparse, the leaflets often glabrate 



above; northern 16. L. argenteus. 



13. Hairs of the stems and petioles, at least the longer ones, spreading or 

 ascending (17). 

 17. Banner petal sericeous in the center of the back; herbage copiously 

 pubescent; pedicels commonly 4 to 6 mm. long; flowers seldom less 



than 12 mm. long 17. L. barbiger. 



17. Banner petal glabrous or nearly so (18). 



18. Flowers 5 to 7 mm. long; racemes normally dense, many-flowered, 

 more or less verticillate; herbage copiously pubescent. 



18. L. HILLII. 

 18. Flowers 8 to 14 mm. long; racemes not noticeably verticillate (19). 

 19. Leaflets sericeous above; stems copiously to densely pubescent; 

 flowers 8 to 10 mm. long, the corolla normally violet; long-peti- 

 oled basal leaves usually present at an thesis. 19. L. palmeri. 

 19. Leaflets sparsely strigose or glabrate above; stems not densely 

 pubescent; long-petioled basal leaves usually disappearing 

 before anthesis (20) . 

 20. Flowers 12 to 14 mm. long, the corolla pale lavender to red- 

 dish purple; stems sparsely to copiously hirsute with long, 



spreading hairs _ 20. L. blumeri. 



20. Flowers 9 to 11 (rarely 12) mm. long, the corolla normally 

 violet; stems not hirsute, the longer hairs relatively short, 

 ascending 21. L. sitgreavesii. 



1. Lupinus succulentus Dougl. ex C. Koch, Wochenschr. Gaertn. 



Pflanzenk. 4: 277. 1861. 



Roosevelt (Gila County) , Canyon Lake and Camp Creek (Maricopa 

 County), 1,500 to 3,300 feet, open slopes and mesas, March. Arizona, 

 California, and Baja California. 



The plants have extraordinarily large root nodules. The Arizona 

 form is relatively small-flowered. 



2. Lupinus sparsiflorus Benth., PL Hartw. 303. 1848. 



Mohave, Graham, Gila, Maricopa, Pinal, Pima, and eastern Yuma 

 Counties, 4,500 feet or lower, mesas and foothills, preferring sandy 

 soil, January to May. Nevada and Arizona to California, Sonora, 

 and Baja California. 



In favorable springs this handsome lupine colors extensive areas 

 with the rich violet of its flowers. The common form in Arizona, with 

 flowers not more (usually less) than 1 cm. long, is interpreted by 

 Smith as var. arizonicus S. Wats. (See footnote 66, p. 434, Smith, p. 

 121). 



3. Lupinus arizonicus S. Wats., Amer. Acad. Arts and Sci. Proc. 12: 



250. 1877 (in part). 



Lupinus concinnus var. arizonicus S. Wats., Amer. Acad. Arts 



and Sci. Proc. 8: 537. 1873. 

 Lupinus sparsiflorus var. barbatulus Thornber ex C. P. Smith, 



Torrey Bot. Club Bui. 47: 497. 1920. 



Mohave and Yuma Counties, eastward to the western part of Mari- 

 copa, Pinal, and Pima Counties, 3,000 feet or lower, usually in sandy 

 washes, February to May. Western Arizona, southeastern Cali- 

 fornia, Sonora, and Baja California. 



