From the Greek echinos, a hedgehog, opsis, like; the spiny plants resemble a rolled-up hedgehog (Cactaceae). Hedgehog cactus. Greenhouse cacti, first introduced in the early nineteenth century, among the commonest cactus plants in cultivation. They are globular when young, columnar with age. They have several deep ridges or ribs with areoles and stiff spines; their large, often fragrantopen for about 36 hours.
E. eyriesii, to 6 inches tall, 11-18 ribs, flowers white, fragrant, Mexico. E. leucantha, 14 ribs, strong spines, flowers brownish-green outside, inside white, Chile, western Argentina. E. multiplex, makes many offsets, pale green body, ribs 13-15, flowers pink, fragrant, southern Brazil. E. tubiflora, globular when young, columnar with age up to 18 inches in height, flower a long tube, white to pink, brown on the outside, southern Brazil.
The compost should be made up from an average potting compost with a sixth part of coarse sand, grit and broken brick added, in well-drained pots. Give the plants a sunny place in a window or greenhouse. Repot every two or three years.
Some species flower better if their offsets are removed. Temperatures: March to September, 65-75 °F (18-24°C), September to March, 40-45°F (4-7°C). Propagation is by rooting offsets which are usually freely produced; some form roots while still attached to the parent plant. New kinds are raised from seed when offsets are not available; sow in a good seed compost, in a temperature of 70°F (21°C); keep the seedlings moist and shaded and prick them off when large enough to handle and the cotyledon has been absorbed.