How to grow
Transplant at almost any season in sandy or loamy soil, and give moderate irrigation to keep the soil well moistened. Plants grow readily from seed sown in flats in sandy loam, with part shade and with enough irrigation to keep the soil moist. They grow outside and indoors and are not injured by twenty degrees of frost; in colder climates they may be grown in conservatories or given protection out of doors.
Harem Cactus; Mound Cactus (Echinocactus polycephalus)
(Named polycephalus from the many heads or stems of the plant)
How to identify and how it grows
The Harem Cactus is so called because on the desert these plants grow in great clumps or colonies, one in the group much taller than all the others. These large clumps have forty or more stems in mounds five feet or so across, and from six to eighteen inches tall, with one or more large stems in the center of each mound. Some of these stems are as much as eight inches in diameter. On them appear twelve to eighteen ridges whose crests are sharp and waxy. The main body of the plant is almost hidden by its dense stout coat of spines, of which there are four to eight radials and four centrals. All thorns are cross-ridged and a grayish pink with occasional bands of a deeper color. The flowers form in a cluster in the center of the stem heads and are about two and one-half inches long. Each flower is composed of nearly one hundred petals and sepals, together, bright yellow and purple-red. These blossoms are partly hidden by the long sharp stout spines. The fruit is elliptical and covered with dense woolly creamy white hairs. This plant grows in stony or rocky soils with plenty of exposure.
How to grow
Set out plants early in spring in rocky or stony soil with sunny exposures, and give enough irrigation to keep the soil moist. Sow the seed in fine sandy loam in flats or pots in part shade, and water enough to keep the soil lightly moist. The plants grow indoors and out and are not injured by twenty degrees of frost; in colder weather they require protection.
Mexican Fruit Cactus (Echinocactus hamatacanthus—Echinocactus longihamatus)
(Named hamatacanthus from the hooked spines)