In the August edition of the Journal of the Mammillaria Society, Wolfgang Plein and Helmut Rogozinski describe a new species of the Series Mammillaria, originally discovered by Jean-Marc Chalet after whom the species is named.
It grows in an area between Los Altares, Dgo. and El Salto, Dgo, and area which had hardly been explored until Jean-Marc Chalet went there and found these plants.
The Holotype, JMC4893 is deposited at the Herbario del Insituto del Botanica de la Universidad de Guadalajara. This is a photo of a habitat plant, albeit rather dry and shrivelled.
Here is a plant of the same species, nicely hydrated, JMC5133, at the same locality as JMC4893 from La Soledad, Dgo.
Full details are available to members of the Mammillaria Society in the August journal. Seedling plants in 5cm pots are available also to members only at the moment.