72 



THE CACTACEAE. 



r 



Fig. 106. — Frtjit of Pachycercus pecten-aboriginum. 



r - 



.v- 



1 T 



' "j 



t .. 



r -* 



"1 ■* 



■,,-5 



"1 



J < 



u ./( 



5. Pachycereus grandis Rose, Contr. U. S. Nat. Herb. 12: 421. 1909. 



Cereus hergeriamis Vaupel, Monatsschr. Kakteenk. 23: 24. 1913. 



Plant 6 to 10 meters high, either simple or much branched, the trunk sometimes a meter in 

 diameter; branches, when present, columnar, generally simple, becoming erect almost from the first,- 

 with numerous constrictions, pale green, or when young glaucous, with some bloom which persists 

 in streaks; ribs 9 to 11, acutish, high; sterile areoles circular, large, bearing white felt and subulate 

 spines, 2 to 3 *cm. apart, not running together, not extending below the spines as in P. peclen- 

 aboriginum; old spines grayish to white with black tips; radial spines 9 or 10; central spines 3, the 

 lower one longer, sometimes 6 cm. long, somewhat flattened; flowering areoles large, elliptic, bearing 

 acicular or bristle-like spines; flowers rather small for the genus, about 4 cm. long; ovary and flower- 

 tube bearing small, acuminate scales, their axils filled with downy hairs; fruit large, globular, dry, 

 covered with long yellow bristles and yellow felt. , 



Type locality: On the pedregal near Cuernavaca, Mexico. 

 Distribution: Common in the State of Morelos, Mexico. 



This plant is very common on the pedregal north of Cuernavaca, where it was first 

 observed by Dr. Rose in 1906 (No. 1 1087), and is frequent on the hills south of Cuernavaca. 



Mr. Dowell, the cactus dealer in Mexico Citv, told Dr. Rose that he had exDorted plants 



E 



specimen 



Washington Botanical Garden 



■■:H. 





> ■ 



^ A. 



h . 



I 



Vi, 



J- f 



-^ -r' 



J T 



^> 



> 



J ^ 





1909 



6. Pachycereus chrysomaUus (Ivcmaire) Britton and Rose, Contr. U. S. Nat. Herb. 12: 421. 



Pilocerejis chrysomaUus Lemaire, Fl. Serr. 3: under pi. 242. 1847. 



Cereus chrysomaUus Hemsley, Biol. Centr. Amer. Bot. i: 541. 1880. 



Cephalocereus chrysomaUus Schumann in Engler and Prantl, Pflanzcnfam. 3*'>a: 182. 1894. 



Pilocereus fulviceps Weber in Schumann, Gesamtb. Kakteen 176. 1897. 



Cereus fulviceps Berger, Rep. Mo. Bot. Gard. 16: 64. 1905. 



Stem columnar, massive, at first simple, but in very old plants much branched, giving off 

 hundreds of erect branches which form arj almost compact cylinder up to 5 meters in diameter, 

 becoming 12 to 18 meters high; branches glaucous green, 11 to 14-ribbed; flowering branches capped 



' [ 



-J 



f \ 



