22 THE FANTASTIC CLAN 



easily accessible. The trunk is usually unbranched, cylin- 

 drical in young plants, two or three inches in diameter, 

 yellow-green with a scurfy waxy coating; and it is not tough. 

 A large tree can be cut down with a small pocketknife in 

 some instances. The twenty or twenty-five radial spines are 

 changed over into long coarse white hairs, four to twelve 

 inches long or even longer, and form a dense covering; hence 

 the common and specific names. Old Man Cactus and senilis. 

 These radials are crooked, flattened, and twisted, while the 

 one to four central thorns are easily pulled out, all spines 

 very fragile. In maturity a dense mass of tawny wool ap- 

 pears around the head of the plant. The rose-colored blos- 

 soms are two inches long, shaped like a bell or funnel, and 

 appear only on the older cacti. They open at night and 

 close in the early morning. The fruit is about the size of 

 a large strawberry; it, too, is rose-colored and covered with 

 scales and tufts of wool. 



How to grow 



Plants may be grown from seed in flats or pots, but the 

 seed is rare and diflUcult to get. Commonly young plants are 

 purchased and grown in pots in gravelly, sandy limestone soil. 

 Water sufficiently to keep the soil slightly moist. A bright 

 sunny location is best. The plants are tender to frost and 

 thrive best in warm conservatories or greenhouses. The 

 Old Man Cactus is a popular plant for rock gardens and is 

 found in many homes both in this country and abroad. 



Pipe Organ Cactus; Pitahaya (Cereus Thurberi) 



(Named in honor of George Thurber, botanist of the 

 Mexican Boundary Commission) 



How to identify and how it grows 



These are large, columnar, symmetrical plants ten to 

 twenty feet tall; the large columns of yellow-green stems, 



