892 CONTKIBUTIONS FROM THE NATIONAL HEEBAEIUM. 



of white wool 1 to 2 cm. long, 1 to 2 mm. apart; spines 15 to 25, acicular, 1 

 to 5 cm. long, yellowish brown when young ; flowers " light green," 5 to 7 cm. 

 long; scales on the ovary and lower part of the flower tube few, minute, acute; 

 scales on upper part of the tube and outer perianth segments broadly ovate, 

 acute ; inner perianth segments oblong, acute ; stamens included ; style long 

 esserted ; fruit depressed, brownish, somewhat ridged, 4.5 cm. long. 



7. Cephalocereus chrysacanthus (Weber) Britt. & Rose, Contr. U. S. Nat. 



Herb. 12: 416. 1909. 



Pilocereus chrysacanthus Weber; Schum. Gesamtb. Kakt. 178. 1S97. 



Cereus chrysacanthus Orcutt, West Amer. Sci. 13: 63. 1902. 



Puebla and Oaxaca ; type from Teliuacan, Puebla. 



Plant 3 to 5 meters high, branching near the base ; branches erect or ascend- 

 ing, glaucous ; ribs about 12 ; areoles about 1 cm. apart ; spines 12 to 15, the 

 longer ones 3 to 4 cm. long, at first golden yellow, becoming darker in age; 

 flowers borne in definite zones on one side of the branch, accompanied by 

 dense masses of long white hairs, nocturnal, 7 to 8 cm. long, rose-red ; fruit 

 smooth, reddish or purplish, about 3 cm. in diameter, the flesh red ; seeds 

 black. 



8. Cephalocereus cometes (Scheidw.) Britt. & Rose, Contr. U. S. Nat. Herb. 



12: 416. 1909. 



Cereus cometes Scheidw. Allg. Gartenz. 8: 339. 1840. 



Pilocereus jubatus Salm-Dyck; Forst. Handb. Cact. 356. 1846. 



Cereus flavicomus Salm-Dyck, Cact. Hort. Dyck. 1849. 202. 1850. 



San Luis Potosl. 



Erect, cylindric ; ribs 12 to 15, hardly tuberculate, obtuse ; areoles close 

 together, round; spines unequal, straight, spreading, 2 cm. long or less, flesh- 

 colored or brownish, becoming gray; flowering areoles bearing masses of yel- 

 low hairs or wool, longer than the spines. 



9. Cephalocereus leucocephalus (Poselger) Britt. & Rose, Contr. U. S. Nat. 



Herb. 12: 417. 1909. 



Pilocereus leucocepliahis Poselger, Allg. Gartenz. 21: 126. 1853. 



Pilocereus houlletii Lem. Rev. Hort. 1862: 428. 1862. 



Pilocereus foersteri Lem. Illustr. Hort. Lem. 13: under pi. lilt. 1866. 



Sonora and Chihuahua; type from Horcasitas, Sonora. 



Plants 2 to 5 meters high, branched below, the branches 3 to 15, erect or 

 ascending; ribs usually 12, low; spines about 10 in each cluster, acicular, 12 

 to 20 mm. long; flowering areoles clustered on one side of the plant toward 

 the top and producing an abudance of long white hairs (sometimes 4 to 10 

 cm. long). 



10. Cephalocereus sartorianus Rose, Contr. U. S. Nat. Herb. 12: 419. 1909. 

 Veracruz. 



Plant 3 to 5 meters high or more, with nearly erect branches, these 7 to 

 10 cm. in diameter, bluish or bluish green; ribs 7, 2 cm. high, marked by a 

 pair of grooves descending obliquely, one on each side, from each areole; 

 areoles usually 1.5 cm. apart; radial spines at first 7 or 8, others apparently 

 developing later; central normally one; all spines short, 1 cm. long or less, 

 at first straw-colored, in age grayish ; all areoles producing few or many cob- 

 webby hairs; flowering areoles appearing on one side of the plant, producing 

 long white hairs 4 to 6 cm. long ; flowers 6 to 8 cm. long, " dirty rose-red " ; 

 fruit red. 



