Plate No. 16

Brain Cactus

Stenocactus multicostatus

"Wavy ribs in a tight sphere"

Native to

Highlands of north-central Mexico

Botanical illustration of Brain Cactus
Stenocactus multicostatus — drawn from life
History

A brief account

Its many narrow, undulating ribs give the appearance of cerebral folds. First described in the 19th century, the brain cactus is a slow-growing miniature that has become a prized addition to the collector's windowsill.

How to care for

Brain Cactus (Stenocactus multicostatus) grows best when its natural cycle of strong light, freely draining soil and measured watering is respected. Give it bright direct sun. Water it according to its seasonal needs: lightly every two weeks in summer; dry in winter. Plant it in very mineral, fast-draining cactus mix. A container with an unobstructed drainage hole is essential, because moisture lingering around cactus roots can quickly lead to rot. Keep its temperature needs in mind: 5–30°c. cool winter rest for spring bloom. During active growth, check the compost before watering rather than following a rigid calendar, since heat, light and pot size all change how quickly it dries. Reduce watering during cool or dormant periods, keep the plant well ventilated, and wait until the growing medium is dry before watering again.

How to propagate

Almost always from seed. Sow fresh seed on the surface of a fine, sterile cactus mix and keep it warm, lightly humid and out of harsh direct sun until germination. Once seedlings are established, increase ventilation gradually and allow longer intervals between watering to reduce the risk of damping off. Young cacti are especially vulnerable to excess moisture. Use a small pot with excellent drainage, provide bright filtered light while roots establish, and move the new plant gradually into the light, temperature and watering conditions preferred by a mature Brain Cactus.
Cultivation

Quick tips for care & planting

Light
Bright direct sun.
Water
Lightly every two weeks in summer; dry in winter.
Soil
Very mineral, fast-draining cactus mix.
Temperature
5–30°C. Cool winter rest for spring bloom.
Propagation
Almost always from seed.