STANDLEY TREES AND SHRUBS OF MEXICO. 519 



2. Erythroxylon lucidum H. B. K. Nov. Gen. & Sp. 5 : 179. 1822. 



Reported from Mexico, but no specimens seen by the writer. Costa Rica to 

 Colombia ; type from Colombia. 

 Small tree ; leaves S to 15 cm. long. 



3. Erythroxylon havanense Jacq. Enura. PI. Carib. 21. 1760. 

 Oaxaca and Veracruz. Cuba ; type from Havana. 



Shrub or small tree, 6 meters high or less ; leaves 3 to 8 cm. long, pale 

 beneath ; flowers white ; fruit 4 to 7 mm. long, orange or yellow. 



4. Erythroxylon mexicanum H. B. K. Nov. Gen. & Sp. 5 : 178. 1822. 



Sonora to Tamaulipas, Veracruz, and Guerrero; perhaps also in YucatAn; 

 type from Chilpancingo, Guerrero. 



Shrub, 1.5 to 3 meters high ; leaves 3 to 7 cm. long, pale beneath ; fruit 6 to 

 10 mm. long. " Pata de pjljaro " (Sinaloa). 



5. Erythroxylon compactum Rose, Contr. U. S. Nat. Herb. 8: 313. 1905. 

 Puebla and Oaxaca ; type from TehuacS.n, Puebla. 



Shrub, 3 meters high or less ; leaves mostly 1 to 1.5 cm. long ; flowers mostly 

 solitary. 

 This and the next species are very closely related. 



6. Erythroxylon pringlei Rose, Contr. U. S. Nat. Herb. 8: 314. 1905. 

 Known only from the type locality, near Iguala, Guerrero. 



Shrub or small tree, 3.5 to 4.5 meters high ; leaves 1.5 to 3 cm. long ; fruit 

 red, 7 to 8 mm. long. 



7. Erythroxylon pallidum Rose, Contr. U. S. Nat. Herb. 8: 314. 1905. 

 Vicinity of the type locality, San Juan Capistrano, Zacatecas. 

 Shrub ; leaves 2 to 3 cm. long. 



67. ZYGOPHYLLACEAE. Lignum-vitae Family. 



Shrubs or trees, unarmed, often strong-scented and resinous ; leaves opposite 

 or alternate, simple, digitate, or pinnate, the leaves or leaflets entire; flowers 

 perfect, regular or nearly so; sepals 5, free, usually imbricate; petals 5; sta- 

 mens twice as many as the petals ; fruit a capsule, often splitting into several 

 carpels. 



Leaves mostly opposite, digitate or even-pinnate. 



Leaves digitate, usually 3 or 5-foliolate ; flowers pink or purplish. 



1. FAGONIA. 

 Leaves even-pinnate ; flowers yellow, blue, or violet. 



Leaflets 2; petals yellow 2. COVILLEA. 



Leaflets more than 2 ; petals blue or violet. 



Stamens with scalelike appendages at base; stipules persistent. 



3. PORLIERIA. 



Stamens not appendaged ; stipules deciduous 4, GUAIACTJM. 



Leaves mostly alternate, odd-pinnate or simple. 



Fruit covered with long straight hairs; leaves simple, linear or oblanceolate. 



Flowers yellow 5. SERICODES. 



Fruit tomentose or puberulent ; leaves pinnate or, if simple, oval. 



Flowers purplish; petals 4; leaves pinnate 6. MORKILLIA. 



Flowers yellowish; petals 5; leaves usually simple 7. VISCAINOA. 



