STANDLEY TEEES AND SHRUBS OF MEXICO. 1237 



3. PETREA L. Sp. PI. 626. 1753. 



1. Petrea arborea H. B. K. Nov. Gen. & Sp. 2: 282. 1817. 



Petrea mexicana Schiede, Linnaea 6: 373. 1831. 



Petrea ovata Mart. & Gal. Bull. Acad. Brux. 112; 329. 1844. 



Guerrero to Tamaulipas, Veracruz, Yucatan, Tabasco, and Chiapas. Central 

 and South America. 



Large woody vine; leaves opix)site, short-petiolate, elliptic-oblong to elliptic- 

 oval or obovate-oblong, 4.5 to 14 cm. long, obtuse or acute, often subcordate 

 at base, entire, coriaceous, scaberulous ; flowers blue, in long pendent racemes ; 

 calyx tube very short, the lobes oblong or linear-oblong, in fruit 1.5 to 2 cm. 

 long, blue, obtuse or acute; corolla funnelform, about 1 cm. long; fruit a 

 small coriaceous indehiscent capsule. " Opp tzimin " (Yucatitn, Maya) ; " toto- 

 postillo," "soltero" (Oaxaca) ; " bejuco de caballo " (Yucatan, Veracruz);' 

 " raspa-sombrero," " jazmfn," " coamecate azul " (Veracruz); "choreque" 

 (Costa Rica); " buira " (Panama); " hoja chigiie " (Nicaragua); " flor de 

 Santa Maria" (Tabasco); " jazmin azul," " chaparrito " (Colombia); 

 "adelfa," "flor de Jestis," "lengua de vaca," " Adolfina " (El Salvador). 



The vine is an extremely showy one when in flower, and it (or P. volu'biUs 

 L.) is sometimes cultivated as an ornamental plant under the name of "pur- 

 ple wreath." The tough stems are employed as a substitute for rope. 



Petrea volubilis L. has been reported from Mexico but probably incorrectly. 



4. CITHAREXYLXJM L. Sp. PI. 625. 1753. 

 Shrubs or trees ; leaves opposite or ternate, entire or toothed ; flowers small, 

 in axillary or terminal racemes, rarely solitary in the leaf axils; calyx tu- 

 bular-campanulate, truncate or 4 or 5-dentate, persistent in fruit ; corolla tube 

 cylindric, the limb 5-lobate, the lobes subequal; stamens 4; fruit drupaceous. 

 The fruits of some species are edible. The plants are used in domestic 

 medicine, emmenagogue and pectoral properties being ascribed to them. Some 

 species furnish hard strong wood, which is useful for various purposes. The 

 following vernacular names are reported for plants of the genus whose specific 

 identity is uncertain: " Chachalaca " (Michoaean) ; " naranjillo," " teptsi," 

 " roble," " roble amarillo " (Veracruz); " comida de cuervo " (Durango). 

 Flowers solitary in the leaf axils or in 2 to 4-flowered racemes. 



Leaves less than 1 cm. long 1. C. brachyanthum. 



Leaves 2 to 6 cm. long or more, glabrous or pubescent. 



Leaves glabrous beneath or very minutely and obscurely puberulent. 



2. C. tetramerum. 

 Leaves hirtellous or tomentose beneath. 



Calyx in fruit 4 to 4.5 mm. long ; leaves mostly rounded at base. 



3. C. altamiranuni. 



Calyx in fruit 2 to 2.5 mm. long; leaves decurrent at base 4. C. rosei. 



Flowers in elongate many-flowered racemes. 



Leaves copiously hirtellous or pilose beneath with spreading hairs. 

 Leaves flabelliform, 13 mm. long or less, creuate-lobate. 



5. C. flabellifolium. 

 Leaves never flabelliform, much larger, entire or serrate. 



Leaves stellate-tomentose beneath 6. C. rugendasii. 



Leaves pubescent with simple hairs. 

 Flowers 9 to 15 mm. long. 



Leaves densely hirtellous beneath ; calyx 6 to 7 mm. long. 



7. C. kerbeix 



Leaves glabrous beneath except in the axils of the lateral nerves; 



calyx 4 mm. long 8. C, trinerve. 



79688—24 ^26 



