FLOWERING PLANTS AND FERNS OF ARIZONA 531 



3. Tragia nepetaefolia Cav., Icon. PL 6: 37. 1801. 



Tragia ramosa Torr., Ann. Lye. X. Y. 2: 245. 1826. 



Apache County to Coconino County, south to Cochise, Santa 

 Cruz, and Pima Counties, 2,500 to 7,000 feet. Texas to Arizona and 

 Mexico. 



8. RICINUS. Castor-be ax 



Glabrous herb, shrub, or tree; leaves long-petioled, mostly 7- to 

 10-lobed; stipules membranous, sheathing, caducous; inflorescence 

 racemose or paniculate, the pistillate flowers above, the staminate 

 ones below; staminate calyx mostly 5-lobed, the filaments united 

 into many dendritic androphores; pistillate calyx 5-lobed, caducous, 

 the ovary 3-celled, mostly echinate, the ovules solitary, the styles 3, 

 bifid, papillose, red; capsule mostly echinate; seeds large, carunculate. 



1. Ricinus communis L., Sp. PI. 1007. 1753. 



Fort Verde (Yavapai County) and pretty well naturalized near 

 Superior (Pinal County). Introduced from Old World tropics. 



A poisonous plant well known as the source of castor oil, the use 

 of which is not confined to medicine as it is also a valuable lubricant 

 and enjoys many minor uses. The plant is sometimes cultivated 

 as an ornamental and to provide shade for fowl. 



9. JATROPHA 



Perennial herbs, or shrubs; leaves simple, alternate; stipules small 

 or none; flowers monecious or dioecious, borne in terminal or lateral 

 cymes, or the pistillate flowers sometimes solitary; calyx 5-lobed; 

 petals 5, more or less connivent into a tube; stamens 8 to 10, the fila- 

 ments united below into a column, the anthers in two whorls, the 

 lower whorl of 5 and the upper one of 3 to 5 anthers; ovary 1- to 3- 

 celled, the ovules solitary; styles 1 to 3, entire or shortly bifid ; seeds 

 large, carunculate. 



Key to the species 



1. Leaves palmately lobed; perennial herb 1. J. macrorhiza. 



1. Leaves not palmately lobed except on seedlings or suckers; shrubs (2). 



2. Leaf blades obovate-obcordate to spatulate, 5 to 11 mm. long, the petioles 



about 1 mm. long 4. J. spathulata. 



2. Leaf blades about as broad as long, widest near the base, mostly 2 cm. or 

 more long at maturity, the petioles 1 cm. or more long (3). 

 3. Leaves glabrous, cordate-deltoid, the apex acuminate, the margin crenate. 



2. J. CARDIOPHYLLA. 



3. Leaves canescent at least beneath, orbicular-reniform, the margin entire. 



3. J. CAXESCEXS. 



1. Jatropha macrorhiza Benth., PL Hartw. 8. 1839. 



McNary (Apache County), Cochise, Santa Cruz, and Pima Coun- 

 ties, 3,700 to 7,400 feet, mesas and plains. Southern Xew Mexico, 

 Arizona, and Mexico. 



The species is represented in Arizona by var. septemfida Engelm. 

 (J. arizonica Johnston). The large thick root is stated to be 

 strongly purgative. 



