Mammillaria heyderi aka Ball Cactus

Mammillaria heyderi is a cactus. It belongs to the Cactaceae family. Its native range runs from the southeast of Arizona to the southwest of Oklahoma. It also grows in the north of Mexico. Kew places it in deserts and dry shrubland. Kew calls its form a succulent subshrub: a small shrub with fleshy parts. This gives a broad view of its wild home. It does not tell us its needs in a garden. The RHS says it is not native to Britain or Ireland.

English names include Heyder's pincushion and pancake pincushion. They also include nipple cactus and small-spined cream pincushion. LLIFLE lists biznaga de chilillos as a Spanish name. It lists Híkuli as a Tarahumara name. Old plant names include Cactus heyderi and Neomammillaria heyderi. LLIFLE treats both as names for Mammillaria heyderi. In that source, all three names mean the same species. The RHS, though, leaves the name's status unresolved.

LLIFLE says the species has one spine at the centre. It has 15–22 radial spines around that central spine. The species entry gives no spine length or colour. It gives no full-grown height or spread, either. The sizes supplied refer to named forms or subspecies. They do not tell us the species' garden size. The sources give no stem colour for the species itself. They give no facts about bark or leaves.

LLIFLE says the flowers have a cream base colour. Their midveins, or middle veins, have brown and green tones. These facts concern the species, not a named form. The supplied species account gives no month for bloom. It does not state flower size or how pollination takes place. The red fruits are edible and known as chilitos. This shows that people can use the fruit as food. It does not show that other parts are edible. The sources give no broader review of safety for people or pets.

The supplied species sources say little about how to grow it. They do not set its water, light, or soil needs. Nor do they set frost limits. Care notes elsewhere refer to named forms, not this species as a whole. No supplied source on the species describes pests or diseases. None states how fast it grows. The sources do not confirm its hardiness or landscape uses.