STANDLEY TKEES AND SHRUBS OF MEXICO. 349 



Plants unarmed, low shrubs or herbs. Fruit broadly oblong. 



3. NEPTUNIA. 

 Plants usually armed with spines, trees or large shrubs. 



Fruit thin, bivalvate 4. PIPTADENIA. 



Fruit thick and hard, indehiscent 5. GOLDMANIA. 



Anthers without glands. 



Stamens as many as the corolla lobes or twice as many. 



Fruit with a persistent continuous margin, the valves separating from 

 it ; plants usually armed with spines ; flowers capitate or spicate. 



6. MIMOSA. 

 Fruit without a i>ersistent marghi ; plants unarmed ; flowers capitate. 



Seeds longitudinal or oblique; low shrubs or herbs 7. ACUAN. 



Seeds transverse ; trees or large shrubs 8. LEUCAENA. 



Stamens more than twice as many as the corolla lobes. 



Stamens free. Flowers capitate or spicate; plants spiny or unarmed. 



9. ACACIA. 

 Stamens united. 



Fruit elastically bivalvate. Plants unarmed ; flowers capitate. 



10. CALLIANDRA. 

 Fruit not elastically dehiscent. 



Valves of the fruit separating from the persistent margin. Plants 



unarmed; flowers spicate or capitate 11. LYSILOMA. 



Valves of the fruit not separating from the margin. 



Valves of the fruit thin, very broad, straight. Flowers capitate. 



12. ALBIZZIA. 

 Valves thickened, often curved, twisted, or coiled. 



Fruit coiled, very broad, indehiscent ; flowers capitate ; plants 



unarmed 13. ENTEROLOBIUM. 



Fruit not coiled, usually narrow and indehiscent ; flowers capi- 

 tate or spicate ; plants usually spiny. 



14. PITHECOLLOBIUM. 



1. ENTADA Adans. Fam. PI. 2: 31S. 1763. 

 Scandent shrubs, often armed with spines ; leaves bipinnate, the leaflets few, 

 large ; flowers small, spicate ; fruit large, breaking up into 1-seeded joints. 

 Plants armed with vei-y numerous recurved spines ; fruit about 2 cm. wide. 



1. E. patens. 

 Plants unarmed ; fi'uit 5 to 6 cm. wide 2. E. polystachia. 



1. Entada patens (Hook. & Arn.) Standi. 



Inga, patens Hook. & Arn. Bot. Beechey Voy. 419. 1841. 



Piptadcnia patens Benth. Bot. Voy. Sulph. 89. 1844. 



Mimosa (jualanensis Robins. &. Bartl. Proc. Amer. Acad. 43: 53. 1907. 



Guerrero. Guatemala and Nicaragua ; type from Nicaragua. 



Leaflets 3 to 6 pairs, 1.5 to 5 cm. long, oval or orbicular, nearly glabrous; 

 flowers yellowish white; fruit about 13 cm. long, glabrous, often somewhat 

 constricted between the seeds. 



The Guerrero plant has more numerous pinnae and leaflets than the Central 

 American one, and may be distinct. 



2. Entada polystachia (L.) DC. Mem. Legum. 12. 1825. 

 Mimosa polystachia L. Sp. PI. 520. 1753. 



Sinaloa to Oaxaca and Tabasco. Central America, West Indies, and northern 

 South America. 



