STAISTDLEY TREES AND SHRUBS OF MEXICO. 397 



Tree, 6 to 8 meters high ; leaflets 1 to 1.8 cm. long, oblong, puberulent ; flowers 

 white. " Parotillo " (Michoacfm, Guerrero). 



The writer has seen no fruit of this plant, which may belong to some other 

 genus. 



21. Pithecollobium brevifolium Benth. ; A. Gray, PI. Wright. 1: 67. 1852. 

 Havardia hrevifoUa Small, Bull, N. Y. Bot. Gard. 2: 92. 1901. 



Coahuila, San Luis Potosi, and Tamaulipas ; tyi^e collected between Cerralvo 

 and Monterrey, Nuevo Le6n. Southwestern Texas. 



Tree, sometimes 9 meters high, with a trunk 15 cm. in diameter, the bark thin, 

 smootli, gray ; leaves persistent, the pinnae 2 to 5 pairs, the leaflets 10 to 20 

 pairs, 4 to 8 mm. long, pubescent or glabrate ; flowers yellowish white ; fruit 

 flat, straight, 7 to 12 cm. long, about 1.5 cm. wide ; wood hard, close-grained, 

 dark reddish brown, very heavy. " Tenaza " (Nuevo Leon, Tamaulipas); 

 " huajillo " (Texas); " guajilla " (Tamaulipas). 



The tree is of some importance for forage, the leaves being eaten by goats 

 and sheep in winter. The wood is used for various purposes. Specimens col- 

 lected in Oaxaca probably belong to this species, and others from Sinaloa (where 

 the plant is known as " carbonera " ) are probably conspecific. 



22. Pithecollobium albicans (Kunth) Benth. Trans. Linn. Soc. Bot. 30: 592. 

 1875. 



Acacia albicans Kunth, Mimos. PI. Legum. 87. pi. 27. 1819-24. 



Yucatan and Campeche ; type from Campeche. 



Tree, sometimes 20 meters high ; leaflets numerous, 3 to 6 mm. long ; fruit 

 about 10 cm. long. " Chucum " (Yucatan) ; " huisache " (Campeche, Ramirez). 



The tree is said to produce a gum similar to that of mezquite. The fruit is 

 reported to contain 18 per cent of tannin, and to yield a black dye. 



It is probable that the present material is referred here correctly, although 

 it does not quite agree with Bentham's description, especially in regard to the 

 fruit. The type collection was without fruit, and Bentham's description of it 

 was based, presumably, upon specimens from Hidalgo, which may have belonged 

 to some other species. 



23. Pithecollobium sonorae S. Wats. Proc. Amer. Acad. 24: 49. 1889. 



Dry plains or hillsides, Sonora and Sinaloa ; type from Guaymas, Sonora. 



Shrub or small tree, 3 to 6 meters high, with very hard wood ; leaflets numer- 

 ous, 3 to 4 mm. long ; fruit flat, straight, 7 to 9 cm. long, 1.5 to 2 cm. wide. " Una 

 de gato" (Sonora) ; " palo gato " (Sinaloa). 



24. Pithecollobium mexicanum Rose, Contr. U. S. Nat. Herb. 1: 100. 1891. 

 Baja California, Sonora, and Sinaloa ; type from Alamos, Sonora. 



Tree, 4.5 to 9 meters high or larger, or often only a shrub, with smooth 

 brownish bark, armed with short spines ; leaflets few, oblong, about 5 mm. long, 

 pale green ; fruit flat, thin. " Chino " or " palo chino." 



The wood is used for furniture, etc. 



15. INGA Scop. Intr. Hist. Nat. 298. 1777. 



Refebences : Bentham, Lond. Journ. Bot. 4: 577-622. 1845 ; Pittier, Contr. 

 U. S. Nat. Herb. 18: 173-223. pi. 81-105. 1916. 



Unarmed trees or shrubs ; leaves even-pinnate, the leaflets few, large, the 

 petiole often winged ; stipules small ; flowers large, spicate or capitate ; fruit 

 large, the seeds imbedded in a pulp. 



The fleshy pulp surrounding the seeds is edible, and the pods are often seen 

 in the markets. The wood is said to be weak and fibrous, with a specific gravity 

 of 0.54 to 0.67, and to be of little value except for charcoal and firewood. Some 

 of the species are often planted to shade coffee bushes and as windbreaks to 



