THE BABY CACTUS 61 



partial shade, the soil moist but not wet. Plants may be 

 transplanted at any season in sandy, stony, or gravelly soil, 

 and watered once in two or three weeks during dry spells. 



Black Spined Pincushion Cactus 



(Mam m illaria Milleri) 



(Named for Dr. Gerrett S. Miller, Jr., who first collected it 

 near Phoenix, Arizona) 



How to identify and how it grows 



The Black Spined Pincushion, another of the Mammillaria 

 genus of Cactacese, grows from single stems or several stems 

 in clumps which are sometimes branched, and from two to 

 nine inches high, two to three inches in diameter. The 

 stems are globose or cylindrical with the tubercles crowded 

 close together on their lower parts. These tubercles are 

 about one-third of an inch long, and are arranged symmetri- 

 cally in eleven to fourteen rows. There are from seventeen 

 to twenty radially placed spines, widely spreading and about 

 a half-inch long, with a white body and reddish brown tips; 

 also one to three central spines with upturned hooks, brown- 

 ish red appearing black at a distance. The flowers are 

 purple fading out to a pink, and bell-shaped. This handsome 

 desert species strongly resembles the beautiful Sunset Cactus, 

 but has much stouter and darker central spines. 



How to grow 



This plant should be treated similarly to the Sunset Cactus. 

 Young plants grow readily from seed in moist sandy or loamy 

 soil in pots or flats in part shade. Older plants may be trans- 

 planted at almost any season in rocky or gravelly soils and 

 watered once or twice a month during dry seasons. They 

 are not injured by temperatures twenty or twenty-five degrees 

 below freezing, but with greater cold than this must be pro- 

 tected or grown in warm sunny conservatories. 



