290 CACTACEAE (CACTUS FAMILY) 
short, grayish-white bristles, becoming stiff and straw-colored as 
the plants grow old, with usually about four stouter, yellowish- 
brown spines, a half-inch to an inch long. Flowers pale yellow, 
nearly two inches broad. Fruit ovate, inedible, prickly, becoming 
dry at maturity. Seed rather large and thick, with a corky margin. 
Means of control the same as for the preceding species. 
GLOBE CACTUS 
Mamilléria vivipara, Haw. 
Other English names: Ball Cactus, Purple Cactus. 
Native. Perennial. Propagates by seeds. 
Time of bloom: June to July. 
Seed-time: Early in the following summer. 
Range: Manitoba to Alberta, southward to Kansas, Colorado, and 
Utah. 
Habitat: Dry soil; prairies, rocky hillsides, pastures. 
When these small spiny plants occur in pasture land, they are 
most unpleasant weeds, occupying the place of forage too scanty at 
best. This speciés usually grows in tufts, forming 
large flat masses. Stems two to four inches in 
diameter, usually depressed globose, covered with 
fleshy, rather loose, slightly grooved, nearly cylindri- 
cal green tubercles, woolly at base, each bearing a 
central bundle of four to eight reddish brown spines, 
a half-inch or more long, erect or somewhat spread- 
ing, surrounded by fifteen to twenty smaller, radi- 
ating, grayish-white spines in a single row. Flowers 
solitary, growing from small cavities at the base of 
the tubercles, funnel-shaped, nearly two inches long 
wt and about as wide when fully open (which is only 
Fre.203.— for a few hours in bright sunlight) with fringed 
Ball or Globe sepals and narrow, lance-shaped petals, deep purple; 
Cactus (Ma- stamens very numerous and style divided into thread- 
millaria vivi- ,. ‘ . : 3 
para). x3. like, stigmatic branches; ovary inferior, one-celled. 
Fruit a little more than a half-inch long, ovoid, 
pale green, juicy; seed about a twelfth of an inch long, obovoid, 
slightly curved, light brown, the surface finely pitted. (Fig. 203.) 
