STANDLEY TREES AND SHRUBS OF MEXICO. 531 



9. TARAVALIA Greene, Leaflets 1 : 222. 190G. 



1. Taravalia aptera (Parry) Greene, Leaflets 1: 222. 1906. 



Ptelea aptera Parry, Proc. Davenport Acad. 4: 39. 1884. 



Ptelea nucifera Greene, Contr. U. S. Nat. Herb. 10: 75. 1906, 



Ptelea obscura Greene, Contr. U. S. Nat. Herb. 10: 76. 190G. 



Baja California ; type from Baliia de Todos Santos. 



Shrub or small tree, sometimes 5 meters high; leaves alternate, digitate, 

 the leaflets 3, gland-dotted, 1 to 3 cm. long, obtuse or acute ; flowers few, small, 

 white ; fi'uit nutlike, indehiscent. 



10. PTELEA L. Sp. PI. 118. 1753. 



1. Ptelea trifoliata L. Sp. PL 118. 1753. 



Ptelea pentandra Moc. & Sesse; DC. Prodr. 2: S3. 1825. 



Ptelea angnstifolia Benth. PI. Hartw. 9. 1839. 



Ptelea subintegra Greene, Contr. U. S. Nat. Herb. 10:61. 1906. 



Ptelea coahuilensis Greene, Contr. U. S. Nat. Herb. 10: 61. 1906. 



Ptelea oMusata Greene, Contr. U. S. Nat. Herb. 10: 61. 1906. 



Ptelea pvmila Greene, Contr. U. S. Nat. Herb. 10: 61. 1906. 



Ptelea scutcllata Greene, Contr. U. S. Nat. Herb. 10: 62. 1906. 



Ptelea cuspidata Greene, Contr. U. S. Nat. Herb. 10: 62. 1906. 



Ptelea sancta Greene, Contr. U. S. Nat. Herb. 10:63. 1906. 



Ptelea ylauca Greene, Contr. U. S. Nat. Herb. 10: 64. 1906. 



Ptelea acvtifnlia Greene & Rose, Contr. U. S. Nat. Herb. 10: 68. 1906. 



Ptelea megacarpa Rose; Greene, Contr. U. S. Nat. Herb. 10: 68. 1906. 



Ptelea laetissima Greene & Rose, Contr. U. S. Nat. Herb. 10: 69. 1906. 



Sonora to Tamaulipas and Oaxaca. Widely distributed in the United 

 States. 



Shrub or small tree, sometimes 7 meters high, with a trunk 20 cm. in 

 diameter, the whole plant with a disagreeable odor; bark thin, smooth or 

 nearly so, dark gray, reddish brown on young branches; leaves alternate, 

 digitately 3-foliolate, the leaflets very variable in shape and size, glabrous or 

 pubescent ; flowers greenish white, cymose ; fruit a samara, 1 to 2.5 cm. long ; 

 wood hard, close-grained, yellowish brown, its specific gravity about 0.83. 

 " Cola de zorrillo " (Chihuahua). 



In the United States, where the plant is known as " hop-tree " and " wafer- 

 ash," the fruit has been employed as a substitute for hops. The root has a 

 bitter, pungent, and slightly acrid but not disagreeable taste and a somewhat 

 aromatic odor. It contains the alkaloid berberine. It has been employed as 

 a remedy for dyspepsia and as a mild tonic. 



Many segregates from this species have been published besides the Mexican 

 ones cited above. The species exhibits a large amount of variation, but it 

 seems impossible to divide the specimens into groups by any constant 

 character. Wilson, in the North American Flora, has recognized three species, 

 but the key characters given for the species are obviously of little value. Of 

 the Mexican segregates, P. pumila is the most distinct, because of its very 

 small leaflets. 



11. ZANTHOXYLUM L. Sp. PI. 270. 1753. 



Shrubs or trees, often armed with spines ; lea\es altirnate, even-pinnate, 

 odd-pinnate, or rarely unifoliolate, deciduous or persistent, the leaflets entire 

 or crenulate ; flowers small, whitish or yellowish ; fruit of 1 to 5 follicles. 



The dried bark of two United States species, Z. americanum Mill, and Z. 

 clava-herculis L., which are known as "prickly ash," is oflicial in the U. S. 

 Pharmacopoeia. It contains one or more alkaloids and is used as a stimulant 



