Coryphantha

Family Cactaceae. Native range - Mexico, the southwestern states of the USA.

There are approximately 80 species and varieties. The shape of these cacti is globose or slightly elongated. The stem is solitary, sometimes producing an offset; gray-green or blue-green in color. In summer large (4 - 10 cm in diameter) flowers appear at the apex of the Coryphantha, usually yellow, more rarely pink or white; they open during the day and last several days. Fruits ripen the following year.

Placement: Plants prefer a bright, sunny and warm location and grow very well on a windowsill. In winter they can be moved to a cool, dry place (KUS).

Care: In summer regular watering is necessary; in winter they are not watered. Plants are planted in loose sandy or gravelly-loamy soil, adding 40% leaf mould. Young plants are repotted in spring, adults every 2 - 3 years, but the top layer of old soil is replaced annually with fresh potting mix. The plant is fertilized once a month with cactus fertilizer.

Pests and diseases: The plant is susceptible to attacks by scale insects, spider mites and aphids. If light is insufficient, the lower part of the plant converts into corky tissue, i.e. the aging process is accelerated.

Propagation: possible by seed.