264 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Plants scandent, the stems mostly herbaceous ; root large, turnip-shaped ; 

 leaves rounded-cordate : flowers white, showy, with a slight fetid odor, ar- 

 ranged in paniculate racemes. " Hierba del iudio " (Tamaulipas) ; " tripas de 

 Judas" (Oaxaca, Reko). Walter reports the name " thusch " from Mexico. 



Palmer states the roots weigh as much as six pounds. 



3. ACHATOCARPUS Triana, Ann. Sci. Nat. IV. 9: 45. 1858. 



Trees or shrubs ; flowers small, dioecious ; perianth 5-lobed ; stamens 10 to 

 20; fruit baccate. 



Leaves densely pubescent beneath 1. A. oaxacanus. 



Leaves glabrous. 



Branchlets aculeate 2. A. gracilis. 



Branchlets unarmed 3. A. m.exicanus. 



1. Achatocarpus oaxacanus Standi., sp. nov. 



Type collected between Jamiltepec and Kio Verde, Oaxaca (Nelson 2358; 

 U. S. Nat. Herb. no. 569298). 



Branches puberulent, armed with slender spines 6 mm. long or less; leaves 

 short-petiolate, obovate-oblong or elliptic-oblong, 5.5 to 6.5 cm. long, 2.5 to 3.5 

 cm. wide, obtuse or rounded at apex, acute to attenuate at base, glabrate above, 

 densely pubescent beneath along the costa ; racemes numerous, few-flowered, 

 2.5 cm. long, or less, the rachis puberulent, the pedicels 1 to 2 mm. long; 

 sepals 2 mm. long, obovate to suborbicular, rounded at apex, minutely puber- 

 ulent or glabrate ; fruit 3 mm. in diameter, glabrous. 



2. Achatocarpus gracilis H. Walt, in Engl. Pflanzenreich IV. 83:137. f. ^1. 



1909. 

 Known only from the type locality, Petathin, Guerrero, altitude 50 meters. 

 Glabrous tree with slender brown branches, armed with straight spines; 

 leaves obovate-lanceolate, 6 cm. long, obtuse ; flowers small, paniculate. 



3. Achatocarpus mexicanus H. Walt, in Engl. Pflanzenreich IV. 83: 139. 1909. 



Veracruz and Chiapas ; type collected between Tapana and La Junta, Chiapas. 



Shrub or tree, glabrous, unarmed ; leaves elliptic, 8.5 cm. long ; flowers race- 

 mose. 



4. PHAULOTHAMNUS A. Gray. Proc. Amer. Acad. 20: 294. 1885. 

 1. Phaulothamnus spinescens A. Gray, Proc. Amer. Acad. 20: 294. 1885. 



Baja California, Sonora (type locality), and Sinaloa. 



Erect glabrous shrub, 1 to 2.5 meters high, with gray branches ; leaves oblan- 

 ceolate, about 1.5 cm. long ; flowers small, in short racemes. 



5. PETIVERIA L. Sp. PI. 342. 1753. 

 1. Petiveria alliacea L. Sp. PI. 342. 1753. 



Pctiveria octandra L. Sp. PI. ed. 2. 486. 1762. 



Petiveria hexandria Sess^ & Moc. Fl. Mex. 98. 1894. 



Baja California to Jalisco, Chiapas. YucatAn, and Veracruz. Widely distrib- 

 uted in tropical America ; type from Jamaica. 



Suffrutescent, about a meter high, or often wholly herbaceous, with a strong 

 odor of garlic; leaves ovate or elliptic, with minute stipules; flowers small, pink, 

 white, or green, in long slender interrupted spikelike racemes. " ZorriUo " 

 (Tabasco, YucatSn, Sinaloa, Nicaragua, MichoacAn, Guerrero); "hierba dc 

 las gallinitas" (Oaxaca, Yucatfin) ; " pay-ch6," " xpay-che " (YucatAn, Maya: 

 "skunk-plant"); "anamfl" (Cuba, Porto Rico, Panama, Colombia, Santo 

 Domingo); " apazote de zorro " (Guatemala); " hisps^sina " (Guatemala): 

 " ipacina " ( Nicaragua ) . 





I 



