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 species 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 cylindrical 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 spreading, surrounded by fifteen to twenty smaller, radiating, 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 and about as wide when fully open (which is only for a few hours in bright sunlight) with fringed sepals and narrow, lance-shaped petals, deep purple; stamens very numerous and style divided into threadlike, 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.)
Fig. 203.-Ball or Globe
Cactus (Mamillaria vivipara). X 1/4.
Small areas may be removed by deep cutting from the roots with a stout hoe or spud, before the maturing of the fruit. Turning the sod with a plow at once destroys the plants.