878 CONTRIBUTIONS FROM THE NATIONAL HEEBARIUM. 



to 6 cm. long; glochids numerous, slender, 4 mm. long or less, white, turning 

 brown, persistent on the old stems ; flowers yellow, 5 cm. broad ; fruit 

 oblong to ovoid, 3 to 4.5 cm. long, its numerous areoles bearing white glochids 

 and some slender spines ; seeds beakless, 5 to 5.5 mm. in diameter. 



31. Opuiitia pumila Rose, Smiths. Misc. Coll. 50: 521. 1908. 

 Central and southern Mexico; type from Oaxaca. 



Stems low, very much branched, the joints readily falling off when touched, 

 6 to 20 cm. long, velvety-pubescent, terete or sometimes slightly flattened, tur- 

 gid, bearing more or less prominent tubercles ; areoles small, those of old stems 

 bearing several slender spines, the longer ones 3 cm. long; areoles of young 

 joints usually bearing 2 yellowish spines ; ovary pubescent, with few spines or 

 none ; petals yellow, tinged with red, 15 mm. long ; fruit globular, red, 15 mm. 

 long. "Cardo," "nopal cardoso " (Oaxaca, Reko) ; " vixivixio " (Zapotec, 

 Reko). 



32. Opuntia pubescens Wendl. ; Pfeiff. Enum. Cact. 149. 1837. 

 Opuntia angusta Meinsh. Wochenschr. Giirtn. Pflanz. 1: 30. 1858. 

 Opuntia leptarthra Weber; Goss. Bull. Mus. Hist. Nat. 10: 393. 1904. 

 Widely distributed in Mexico. Guatemala. 



Plants small, usually low, sometimes 40 cm. high, much branched ; joints 

 easily becoming detached, nearly terete, glabrous or pubescent, 3 to 7 cm. 

 long ; spines numerous, short, brownish ; flowers lemon-yellow but drying i-ed ; 

 fruit 2 to 2.5 cm. long, red, a little spiny, with depressed umbilicus; seeds 3 

 mm. in diameter. 



33. Opuntia decumbens Salm-Dyck, Hort. Dyck. 361. 1834. 

 Opuntia puherula Pfeiff. Enum. Cact. 156. 1837. 

 Southern Mexico. Guatemala. 



Stems low, often creeping or trailing, rarely over 40 cm. high ; joints 10 to 

 20 cm. long, oval to oblong, covered with a short soft pubescence ; areoles usu- 

 ally small, surrounded by a purple blotch, bearing yellow glochids and wool, 

 the wool cobweb-like on very young joints ; spines often wanting, usually soli- 

 tary but sometimes numerous, slender or rather stout, 4 cm. long, yellow ; 

 flowers numerous, small, including the ovary about 4 cm. long ; petals dark 

 yellow; fruit deep purple, very juicy; seeds about 4 mm. broad. 



34. Opuntia depressa Rose, Smiths. Misc. Coll. 50: 517. 1908. 

 Southern Mexico ; type from TehuacAn. 



Low, creeping or spreading plant, sometimes 60 cm. high and forming a 

 patch 3 to 4 meters in diameter; joints dark glossy yellowish green, pubescent 

 when young, obovate, 20 cm. long, usually with 1 long, somewhat curved spine 

 at each areole, sometimes with 1 to 3 shorter ones, all yellowish ; old joints 

 oblong, 30 cm. long, bearing 4 to 6 spines at each areole ; flowers red ; fruit 

 small, globular, witli large clusters of brown glochids, when immature with 

 a broad deep umbilicus. 



35. Opuntia lubrica Griffiths, Rep. Mo. Bot. Gard. 21: 169. 1910. 

 Type from Alonzo. 



Plants low, ascending-spreading, frequently 45 cm. high ; joints subcircular 

 to obovate, 15 to 20 cm. long, glossy, bright green, papillate but scarcely 

 pubescent; areoles 15 to 22 mm. apart, 4 to 6 mm. in diameter; spines very 

 variable, nearly absent or abundant, usually 1 to 3, mostly about 12 mm. 

 long but sometimes 2.5 cm., yellowish, sometimes darker at base; fruit light 

 red, acid ; seeds thin-shelled, about 3 mm. in diameter. 



