Mammillaria coahuilensis

Mammillaria coahuilensis
Date: 1997 March 21

This is a species that the taxonomists seem never to have made up their mind about. I'm using the name from my plant label, but you can also choose Mammillaria (or Porfiria) schwartzii, not to be confused with M. schwarzii which is something else entirely. I grew this plant from seed sown around 1985. It has thick tuberous roots, and tends to be a bit temperamental in cultivation - I had two plants until a few months ago when one rotted!