370 CACTACE^. [part ii. 



a sable muff, and as, consequently, it cannot 

 belong to that genus, it has been called Pilo- 

 cereus. This plant is covered with long white 

 hairs, and, when of small size, it looks very 

 much like an old man's head. In its native 

 country, however, it grows to a great height, 

 and specimens have been imported fifteen feet 

 long, and not more than a foot in circumference. 

 The Peruvian Torch-Thistles (C. hexagonus and 

 peruvianus), in their native country, are upwards 

 of forty feet high, though not thicker than a 

 man's arm. They grow close together without 

 a single branch, and form a singular sort 

 of prickly crest on the summit of some of the 

 mountains in South America. The creeping 

 Cereus [CJiagelliformis) has slender cylindrical 

 trailing stems, which hang down on every side 

 when the plant is grown in a pot. The flowers, 

 which are very numerous, are pink. The night- 

 flowering Cereus (C grandiflorus) only opens 

 during the night, and fades before morning; 

 the rays of the calyx are of a bright yellow when 

 open, and the petals are snow-white. The stem 

 is angular, branched, and climbing, throwing out 

 roots at every joint. The common Torch-thistle 

 (C speciosissimus) is an erect plant, with a 

 three or four angled stem, and very large 

 bright crimson flowers, which are purplish 

 inside ; and C. speciosa, sometimes called Epi- 



