STANDLEY TREES AND SHRUBS OF MEXICO. 355 



•' PioKanguarimbo " (Guerrero); " coyacate " (Guerrero, Bonpland) ; " liui- 

 zache " (Guerrero, Jalisco, Urbina) ; " y6ndiro " (Michoacan, Ramirez) ; " cusa " 

 (Sinaloa). 



This lias been reported fi'oru Mexico as Piptadenia quadrifoUa N. E. Brown, a 

 South American species. 



6. MIMOSA L. Sp. PI. 516. 1753. 

 Reference: Robinson, Proc. Auier. Acad. 33: 305-331. 1898. 

 Trees or shrubs, usually armed with stout spines, occasionally scandent ; 

 leaves bipinnate; petiolar glands commonly absent; flowers small but often 

 bright-colored, capitate or spicate. sessile ; stamens usually long-exserted ; fruit 

 very variable in form, usually compressed, the margin persistent, the valves 

 often breaking into joints. 



Several herbaceous species occur in Mexico. A large number of Mexican 

 species are described by Sess^ and Mocino,' but in most cases it is impossible to 

 identify them. 

 A. Flow'ers spicate. 

 Leaflets 1 or 2 pairs. 



Leaflets <lensely pubescent; fruit coiled 1. M. spirocarpa. 



Leaflets glabrous ; fruit straight. 



I>eaflets 15 to 22 mm. long 2. M. rosei. 



Leaflets 4 to 9 mm. long 3. M. paucifoliolata. 



Leaflets more than 2 pairs, at least in most of the leaves, usually nmch more 

 numerous. 

 Corolln glabrous or nearly so. 



Leaflets few, 1 to 5 or rarely 7 pair.s, elliptic to obovate, less than twice 

 as long as broad. 



Leaflets and fruit glabrous 4. M. laxiflora. 



Leaflets and fruit pubescent. 



Fruit armed with spines 5. M. distachya. 



Fruit unarmed 6. M. purpurascens. 



Leaflets 4 to 20 pairs or more, linear or oblong, more than twice as 

 long as broad. 



Fruit sessile or nearly so , 7. M. polyantha. 



Fruit long-stipitate. 



Valves of the fruit hispid 8. M. polyanthoides. 



Valves of the fruit glabrous. 



Joints of the fruit much broader than long; filaments yellowish. 



9. M. stipitata. 

 Joints of the fruit about as long as broad ; filaments purplish. 



10. M. ionema. 

 Coi'oUa densely sericeous or puberulent. 



Loaflets 4 to 10 mm. wide 11. M. guatemalensis. 



Leaflets 2.5 nun. wide or narrower. 



Stems unarmed 12. M. puberala. 



Stems armed with stout spines. 



Leaflets usually 20 to 40 pairs 13. M. cabrera. 



Leaflets usually less than 20 pairs. 



Spikes oblong, little longer than broad 56. M. monancistra. 



Spikes cylindric, much longer than liroad. 

 Branches covered with minute, sessile or sfpitate glands. 



14. M. adenantheroides. 



'PI. Nov. Hisp. 175-179. 1887. 



