Origin and Habitat: East of Paipote on the hills around the town.

• Copiapoa megarhiza var. microrhiza F.Ritter

• Copiapoa megarhiza Britton & Rose
• Copiapoa brunnescens Backeb.
• Copiapoa krainziana var. brunnescens
• Copiapoa echinata var. borealis F.Ritter

Description: Copiapoa megarhizaSN|9765]]SN|9765]] var. microrhiza today it is only a synonym of Copiapoa megarhizaSN|9765]]SN|9765]], however some differences permits to distinguish it from the standard species. The most distinguishing features of this variety are the smaller and weaker roots-sysytem and the narrower neck between the stem and the the rootstock. However the two plants are quite similar and it is hard to tell apart one from the others.
Habit: Usually it grows solitary, but branched specimens are not rare.
Root: Swollen taproot.
Stem: Depressed globular to slightly cylindrical, grey-green 5-10 cm in diameter.
Ribs: 10-21 tuberculated.
Areoles: Separated 7-10 mm in diameter, brown or light brown (areoles of Copiapoa megarhizaSN|9765]]SN|9765]] are usually only 4-7 mm in diameter).
Spines: Yellow to black, becoming gray as they age.
Central spines: Up to 6 approx 15-40 mm long.
Radial spines: 8-10 and measuring 5-25 mm in length.
Flowers: 2,5 to 4 cm long.
Fruit: Covered with little green scales and measuring about 1 cm in diameter.

Cultivation and Propagation: Need full sun otherwise the bodies tended to elongate in cultivation, but should be protected from excessive heat and sun in summer, Require light watering, good drainage, and deep pot to accommodate tap root. Keep warm and dry in winter to avoid rot. Frost tolerance 0°C.
Propagation: Seeds (offsets rarely), Grafting is often used to speed growth rate and to create a back-up to plants in collection.