32 



THE CACTACEAE. 



never producing long hairs or wool. The plant, although widely distributed in Bahia, is 

 not found in the dry parts where other cacti are common, but prefers the borders of the 

 deserts, growing usually as solitary individuals surrounded by bushes and small trees. 

 The stems, which are erect and usually unbranched, project about the surrounding vegeta- 

 tion. They are of a vivid glaucous-blue color and thus in striking contrast to their sur- 

 roundings. 



Plate iv, figure i , shows the top of a flowering plant in the collection of the New York 

 Botanical Garden. Figure 31 is from a photograph taken in Bahia by Paul G. Russell in 

 1915; figure 32 shows a fruit collected by Dr. Rose at Machado Portella, Brazil; figure 33 

 shows a flower. 



8. Cephalocereus polylophus (De Candolle) Britton and Rose, Contr. U. S. Nat. Herb. 12: 419. 

 1909. 



Cereus polylophus De Candolle, Mem. Mus. Hist. Nat. Paris 17: 115. 1828. . 

 Pilocereus polylophus Salm-Dyck, Cact. Hort. Dyc'k. 1844. 24. 1845. 



Erect, with simple stems 10 to 13 meters high, green; ribs 15 to 18; areoles small, 1 cm. apart 

 or less, bearing white felt but no wool; spines 7 or 8, yellow, straight, spreading; central spine single, 

 longer than the others; flowers 4 to 5 cm. long, about 3 cm. broad at top, narrowly funnelform; 

 free part of tube 6 to 8 mm. long with ridges down the inside; stamens included, inserted on the 

 throat; filaments about 5 mm. long, red; 

 inner perianth-segments probably red, broad 

 and short, rounded at apex; ovary somewhat 

 tuberculate; scales small, without felt, wool, 

 or hairs in their axils; scales of flower-tube 

 small, acute, spreading, with the tip reflexed. 



Type locality: Mexico. 



Distribution: Eastern Mexico. 



In 1909 Dr. C. A. Purpus sent Dr. 

 Rose a small plant labeled Pilocereus 

 polylophus which is probably this species. 

 It is now only about 30 cm. high and 

 may be briefly described as follows : Ribs 

 14, strongly notched below the areoles; 

 areoles white-felted ; spines 3 to 6, at first 

 brown, becoming white, acicular, about 1 

 cm. long. 



The flower of this species is not typical 

 for the genus. We have never seen it in 

 bloom, but it did flower in the Missouri 

 Botanical Garden, August 24, 1905, and 

 our description is based on photographs, 

 specimens, and notes made by Mr. C. H. 

 Thompson at that time. The plant is 

 known in trade also as Cereus nickelsii 

 and is a shy bloomer in cultivation. 

 The name occurs in the Monatsschrift 

 fur Kakteenkunde for 1910 (20:27). 



Cereus angulosus Stieber (Schumann, Gesamtb. Kakteen 175. 1897) belongs here. 



Illustration: Bull. U. S. Dept. Agr. Bur. PL Industr. 262: pi. 9, as Pilocereus polylophus. 



Figure 34 is from a photograph of the plant in flower at the Missouri Botanical Garden 

 in 1905, copied from Bulletin No. 262 of the Bureau of Plant Industry. 



Fig. 34. — Cephalocereus polylophus. 



