434 MISC. PUBLICATION 42 3, IT. S. DEPT. OF AGRICULTURE 



leaflets, inconspicuous or obsolete stipules, and smaller pods; and (2) 

 var.fruticosa (Mill.) Fawc. and Rend. (C. pringlei A. Gray), which is 

 suffruticose and has uniformly linear leaves. The second variety is 

 known in Arizona only from the type collection of C. pringlei in the 

 Santa Catalina Mountains (Pringle 276). 



2. Crotalaria pumila Ortega, Hort. Matr. Dec. 2: 23. 1797. 



Crotalaria lupulina H. B. K., Nov. Gen. et Sp. 6: 402. 1824. 



Cochise, Santa Cruz, and Pima Counties, 4,000 to 5,500 feet, pre- 

 ferring sandy soil, August to October. Florida; Texas to southern 

 Arizona and Mexico. 



Varies greatly in size of the plant and the flowers, and in the number 

 of flowers in the racemes, these 1 to many. The petals are often 

 tinged or streaked with reddish color. 



17. LUPINUS. 66 Lupine 



Plants herbaceous (the Arizona species), annual or perennial; 

 stems leafy or subscapose; leaves digitately compound with 4 to 15 

 leaflets; flowers in terminal racemes or spikes, often showy; calyx 

 strongly bilabiate; petals blue, purple, or white, the keel usually curved 

 and enclosed by the connivent wing petals; stamens dimorphic; pods 

 more or less compressed, sometimes constricted between the seeds. 



Several species are cultivated as ornamentals and most of those 

 occurring in Arizona are handsome plants. The seeds of L. albus 

 are used as food in Europe. It is known that some of the American 

 species, including L. sparsiflorus, common in Arizona, contain alka- 

 loids that are poisonous to livestock, especially to sheep. The seeds 

 are especially toxic, the pods less so, and the herbage is relatively 

 harmless, often containing so little of the dangerous alkaloids that 

 sheep graze the plants without ill effect. Bluebonnets (L. sub- 

 camosus or L. texensis) is the State flower of Texas. 



The taxonomy of this genus is difficult, and authorities differ 

 greatly in their interpretations, particularly of the perennial species. 



Key to the species 



1. Plants annual or biennial (2). 

 2. Keel ciliate; pods oblong, several-seeded (3). 



3. Flowers verticillate, 10 mm. long or longer, the corolla violet blue, the 

 keel ciliate toward the base, both above and below; stems strigose or 

 glabrate, stout, fistulous; leaflets wedge-shaped, widest at the truncate 

 (often slightly retuse) apex, thickish, glabrous above, sparsely strigose 



beneath 1. L. succulentus. 



3. Flowers not verticillate, not more (usually less) than 10 mm. long, the keel 



ciliate toward the base on the lower side, only (4) . 



4. Plant not succulent, drying green; stems slender, or stout but scarcely 



fistulous; leaflets narrowly lanceolate or oblanceolate, seldom more 



than 4 mm. wide, acute or acutish at apex, thin, usually sparsely 



strigose above; corolla when fresh violet blue, occasionally white. 



2. L. SPARSIFLORUS. 



4. Plant somewhat succulent, drying brownish; stems stout, fistulous; 

 leaflets broadly oblanceolate, 5 to 12 mm. wide, rounded and mu- 

 cronate or mucronulate at apex, thickish, glabrous or glabrate above; 

 corolla when fresh pale purplish pink, sometimes drying violet. 



3. L. ARIZONICTJS. 



66 Reference: Smith, C. P. species ltjplnorum. a distributional catalog of lupinus in Arizona. 

 119-143. 1939-40. 



