STANDLEY — TREES AND SHRUBS OF MEXICO. 421 



Leaflets ovate-oblong to orbicular, 4 to 25 mm. wide or larger. 

 Calyx lobes entire or nearly so. Plants unarmed. 



Leaflets 11 to 20 mm. wide 4. C. vesicaria. 



Leaflets 4 to 8 mm. wide 5. C. sclerocarpa. 



Calyx lobes, at least the outer one, pectinate-dentate. 

 Plants armed with spines ; fruit thick and somewhat fleshy, usually 



less than 1.5 cm. wide 6. C. cacalaco. 



Plants unarmed ; fruit thin, 1.5 to 4 cm. wide. 



Leaflets suborbicular, glabrous; fruit 1 or 2-seeded, 1.5 to 2.2 cm. 



wide 7. C. gracilis. 



Leaflets ovate-oblong to oval, pubescent; fruit several-seeded, 2 to 4 



cm. wide 8. C. platyloba. 



Fruit thin, elastically bivalvate ; calyx lobes entire, 

 luflorescence densely ferruginous-tomentose with stellate hairs. 



9. C. eriostachys. 

 Inflorescence not stellate-tomentose. 



I^eaves sessile ; pinnae one pair ; plants armed with spines. 



10. C. sessilifolia. 

 Leaves petiolate ; pinnae more than one pair ; plants usually unarmed. 



Leaflets 6 to 10 pairs or more. 



Pinnae 3 or 4 pairs; young branches piloi=ulous 11. C. laxa. 



Pinnae 5 to 11 pairs or more ; branches glabrous 12. C. pulcherrima. 



Leaflets usually 3 to 5, sometimes 6 pairs. 



Pedicels furnished with sessile or stipitate glands. 

 Leaflets with black glands along the margins. 



13. C. melanadenia. 

 Leaflets without black glands. 



Pedicels and calyx glabrous but furnished with stipitate glands. 



14. C. pannosa. 

 Pedicels and calyx pubescent as well as glandular. 

 Leaflets 2 to 4.5 mm. wide. 

 Leaflets oblong, about 2 nun. wide, usually 4 or 5 pairs. 



15. C. placida. 

 Leaflets oval or orbicular, about 4 mm. wide, usually 3 pairs. 



16. C. phyllanthoides. 

 Leaflets 5 to 25 mm. wide. 



Pedicels very sparsely glandular ; leaflets rhombic. 



17. C. gaumeri. 



Pedicels densely glandular ; leaflets obovate, ovate, or oval. 



Fruit very glandular ; leaflets 3 or 4 pairs, 5 to 14 mm. 



wide 18. C. caladenia. 



Fruit not glandular ; leaflets 2 pairs, 10 to 23 mm. wide. 



19. C. acapulcensis. 

 Pedicels without glands. 



Pedicels jointed below the middle 20. C. califomica. 



Pedicels jointed above the middle, often at the base of the calyx. 

 Leaflets small, 2 to 5 mm. wide. Calyx densely pubescent. 



21. C. palmeri. 

 Leaflets large, most of them 6 to 20 mm. wide or larger. 



Calyx tube 6 mm. wide or less ; stamens about as long as the 



petals 22. C. mexicana. 



Calyx tube 8 to 11 mm. wide ; stamens often long-exserted. 



Stamens long-exserted 23. C. exostemma. 



Stamens about equaling the petals 24. C. yucatanensis. 



