This desert type is the largest genus of the cactus family, comprising over 300 species. It is different from other cacti in that the species do not have ribs and have spirally arranged tubercles, each with an areole at the tip bearing clusters of spines.
M. zeilmanniana, or rose pincushion, from central Mexico, has clusters of four red-brown main spines surrounded by 15—18 bristly, white radial spines. Initially a solitary plant, it grows to form a cluster of glossy green, globe- shaped stems. The violet-pink or purple flowers are produced in spring in a ring around the top of the plant.
Size: Spread 4 in. (10 cm) in four years.
Light: Direct sunlight.
Temperature: Normal warm room from spring to fall. During winter rest period 50°F (10°C). No lower than 40°F (5°C).
Moisture: Keep moist from spring to fall; in winter apply enough water to prevent the soil drying out.
Feeding: Use liquid tomato fertilizer once a month in spring and summer.
Propagation: Sow seed – allow the pulp from the berries to dry, then pick out the seeds — or take offsets by cutting or pulling them away from the parent plant, drying them for 24 hours, then planting.
Special needs: Flowers are produced from part of the stem which grew last year, so a poor growth season means less chance of a good display of flowers the following spring.