Mammillaria carnea

Mammillaria carnea is a small cactus in the Cactaceae family. It grows wild in central and southern Mexico. Records include Veracruz, Guerrero, Puebla, and Oaxaca. Its home has a tropical climate with a dry season. Plants grow on plains and slopes, often near nurse plants. They occur in dry scrub, tropical deciduous woods, and orchard margins. Other cacti and succulents share these sites.

This succulent subshrub can grow alone or form clusters with age. Older plants produce new stems at the base. Stems start round, then lengthen into short columns with rounded tops. They reach about 0.26–0.30 feet [0.08–0.09 metres] tall. Some reach 0.66 feet [0.20 metres]. Stems span about 0.26–0.39 feet [0.08–0.12 metres]. Their colour ranges from blue-green to nearly bronze. Gardeners grow the species as an ornamental cactus.

Firm, four-sided tubercles give the stem its raised, angular surface. These pointed bumps contain milky sap and have a waxy green surface. Yellow wool fills many of the axils between them. The stiff spines can grow straight or bend in an arc. Most groups have four spines, though some have five. They are red-brown or pink-brown, with dark tips. The lowest spine reaches about twice the length of the others. Radial spines may be absent or reduced to bristles.

Pale pink to rose flowers form a ring near the crown. They arise from older axils and have a funnel shape. Each flower measures about 0.05–0.07 feet [0.015–0.020 metres] long. The fruit has a pear-like shape with a blunt end. The supplied species records do not establish a flowering season. Nor do they establish whether any part is edible or toxic.

In cultivation, use a porous cactus mix with a neutral pH. Choose a pot that lets water drain well. Small pots suit the watering guidance better than large ones. Water well during active growth, but avoid excess water. Too much water can cause rot. Give less water in larger pots, and keep plants dry through winter. A summer feed should contain a high level of potassium. Frost can harm this species, though dry plants may cope better. The source suggests a winter rest at 8–12°C. Wild plants remain abundant, but some local groups are shrinking. Farming and cattle ranching have replaced parts of their habitat.