(Photograph = Mammillaria heyderi gummifera, Zacatecas, MX, Amante Darmanin)
Introduction
Mammillaria heyderi is a short, flat cactus that settles firmly in the ground. Sometimes it is even retracted below the soil surface. In such condition it may be difficult to find, especially if it is covered with gravel.
The Details
M. heyderi has six described supspecies: meiacantha, gaumeri, macdougalii, hemisphaerica, applanata, and heyderi. M. heyderi does not form offsets, just solitary stems that are up to 4-inches across. The species has a milky sap. Flowers are often cream colored, but they may be whitish, tan, or tan-pink. Flowers are not generally showy. The fruits are bright red. M. heyderi grows in grasslands and plains from Arizona to Texas and south to the Yucatan Peninsula.
The species is easy to grow in pot culture, but it may lose its natural flatness when it is overwatered.
Mapping the Cacti of Mexico–Mammillaria
