Astrophytum myriostigma 'nudum'
Mexico-Highlands of San Luis Potosi, Nuevo Leon, Tamaulipas.
This species is widespred, so shows extreme variations on rib numbers, amount of flecking etc., resulting many described variety, ssp. and forma names, but they do not appear to be wortwhile recognizing taxonomically...
This form has not flecks on the epidermis. It is very rare and its fat and blue ribs differ from the type which has shiny, smooth dark green epidermis with sharp, thin ribs.