STANDLEY TREES AND SHRUBS OF MEXICO. 525 



Fniit a drupe. 

 Leaves digitately 3 to 7-foIiolate. 



Style lateral 1. SARGENTIA. 



Style terminal 2. CASIMIROA. 



Leaves simple, 1-foliolate, or pinnate. 



Stj'le lateral; leaves linear or nearly so, simple 3. CNEORIDIUM. 



Style terminal ; leaves compound, or, if simple, much broader than linear. 



Stamens as many as the petals 4. STATJRANTHUS. 



Stamens twice as many as the petals 5. AMYRIS. 



Fruit a capsule or samara, or of follicles. 



Corolla gamopetalous ; filaments more or less united with the corolla tube. 



Leaves 1-foliolate 6, ERYTHROCHITON. 



Corolla polypetalous ; filaments free from the petals. 



Ovules 5 or more in each carpel. Leaves simple 7. THAMNOSMA. 



Ovules 2 or 1 in each carpel. 



Fruit a samara or samara-lilie. Leaves digitate, the leafiets 3. 



Carpels of the fruit separating at maturity ; flowers usually perfect. 



8. HELIETTA. 

 Carpels not separating ; flowers polygamous. 



Samara woody, wingless or nearly so 9. TARAVALIA. 



Samara not woody, surrounded by a broad wing 10. PTELEA. 



Fruit a capsule or of 1 or more follicles. 

 Stamens as many as the petals. 

 Flowers unisexual ; plants usually armed with spines. Leaves pin- 

 nate 11. ZANTHOXYLUM. 



Flowers perfect ; plants unarmed. 



Leaves pinnate; fruit of 1 or 3 follicles 12. PILOCARPUS. 



Leaves simple, 1-foliolate, or digitate; fruit a woody capsule. 



13. ESENBECKIA. 

 Stamens twice as many as the petals or more. 

 Calyx deciduous ; leaves digitate. 



Leaves alternate; sepals very unequal 14. PELTOSIGMA. 



Leaves opposite; sepals subequal 15. CHOISYA. 



Calyx persistent ; leaves pinnate. 

 Ovary 2-celled. Leaflets 5 or 7, 3 to 7 mm. long. 



16. MEGASTIGMA. 

 Ovary 5-celled. 



Calyx of 5 distinct or nearly distinct sepals; leafiets 11 to 25. 6 



to 12 mm. long 17. POLYASTER. 



Calyx 5-dentate ; leaflets 5 to 11, 2.5 to 10 cm. long. 



18. DECATROPIS. 



1. SARGENTIA S. Wats. Proc. Amer. Acad. 25:144. 1S90. 



1. Sargentia greggii S. Wats. Proc. Amer. Acad. 25: 144. 1890. 



Nuevo Leon, Tamaulipas, and San Luis Potosi ; type from Monterrey, Nuevo 

 Leon. 



Tree, sometimes 13 meters high ; bark smooth, gray, peeling off in thin plates ; 

 leaves alternate, persistent, digitately 2 or 3-foliolate, 3 to 10 cm. long, obtuse or 

 acutish, nearly glabrous, entire ; flowers small, white ; fruit fleshy, edible, 1.5 to 

 2 cm. long, yellow; seeds brown, 1.2 to 1.4 cm. long. " Limoncillo " (Tamauli- 

 pas, San Luis Potosi); " chapote amarillo " (Nuevo Leon); " naranjillo " 

 (Tamaulipas). 



The wood is said to be used for fuel, carts, and other purposes. 



