STANDEE Y TEEES AND SHRUBS OP MEXICO. 889 



85. Opuntia glaucescens Salra-Dyck, Hort. Dyck. 362. 1834. 

 Mexico. 



Probably erect ; joints erect, oblong-obovate, 12 to 15 cm. long, 5 cm. 

 broad, sometimes narrowed at both ends, pale green, glaucous, usually 

 purplish around the areoles ; areoles filled with gray wool ; spines 1 to 4, 

 elongate, acicular, white, 2.5 cm. long; glochids brownish to rose-colored. 



86. Opuntia grandis Pfeiff. Enum. Cact. 155. 1837. 

 Mexico, but localities not known. 



More or less erect, 60 cm. high or more ; joints oblong, 12 to IS cm. long, 

 erect, when young reddish, glaucous ; spines few, white ; flowers small, 

 a little open, 2 cm. broad ; petals few, narrowly lanceolate, 12 mm. long. 



87. Opuntia chaff eyi Britt. & Rose, Contr. U. S. Nat. Herb. 16: 241. 1913. 

 Zacatecas, the type from Hacienda de Cedros, near Mazapil. 



Perennial by a large fleshy deep-seated root or rootstock often 35 cm. 

 long by 4 cm. in diameter ; stems normally annual, 5 to 15 cm. long, much 

 branched, often weak and prostrate ; joints elongate, 3 to 5 cm. long, 6 

 to 7 mm. broad, slightly flattened, glabrous, pale bluish green or some- 

 times purplish ; areoles small, circular, with white wool in the lower parts 

 and brown wool in the upper parts; spines 1, rarely 2 or 3, acicular, 2 to 3 

 cm. long, whitish or pale yellow ; glochids numerous, pale yellow ; flower 6 

 cm. broad ; petals 7 to 9, pale lemon-yellow, but slightly pinkish on the out- 

 side; ovary deeply umbilicate, somewhat club-shaped, 4 to 5 cm. long, bear- 

 ing flattened tubercles and large areoles filled with white wool ; upper 

 areoles on ovary bearing also white bristly spines ; ovules numerous, borne 

 in the upper third of the ovary. 



5. GRTJSONIA F. Eeichenb. ; Schum. Monatsschr. Kakteenk. 6: 177. 1896. 

 A single species is known. 



1. Grusonia bradtiana (Coulter) Britt. & Rose, Cactaceae 1: 215. 1919. 



Cereus bradtianus Coulter, Contr. U. S. Nat. Herb. 3: 406. 1896. 



Orusonia cereiformis F. Reichenb. ; Schum. Monatsschr. Kakteenk. 6: 177. 

 1896. 



Opuntia 'bradtiana K. Brandeg. Erythea 5: 121. 1897. 



Coahuila. 



Forming dense, often impenetrable thickets 2 meters high or less, very 

 spiny ; stems light green, 4 to 7 cm. thick, with 8 to 10 low, longitudinal, some- 

 what tuberculate ribs ; areoles 1 to 1.5 cm. apart, 3 to 5 mm. in diameter ; 

 leaves linear, fleshy, green, 8 mm. long, early deciduous ; spines 15 to 25, 

 yellowish brown when young, soon becoming white, acicular, terete or slightly 

 compressed, 1 to 3 cm. long, not sheathed, some of the longer ones reflexed; 

 wool white, turning brown, early disappearing ; corolla rotate, opening in 

 bright sunlight, 3 to 4 cm. broad; sepals ovate, acute, fleshy; petals bright 

 yellow, spatulate, fringed ; filaments brownish yellow ; areoles of the ovary 

 with long weak j'ellow spines, white wool, and yellow glochids; berry (accord- 

 ing to Schumann) ellipsoid, deeply umbilicate. "Organillo" (Patoni). 



6. CEPHALOCEREUS Pfeiff. Allg. Gartenz. 6: 142. 1838. 



Elongate cacti, various in habit, mostly columnar and erect, sometimes much 

 branched with a short trunk or in one species with spreading and procumbent 

 branches; in some species the flowering areoles develop an abundance of wool 

 which confluently forms a dense mass called a pseudocephalium either at the 

 top or on one side near the top; in others long wool or hairs grow from the 



