Hello all, I am not familiar with all the cacti genera and species. This one I picked up a few years ago at a local nursery. Typical of nursery plants, it was labeled as "cacti and succulents". As one can see, it is a small, low-growing, spreading species. The new spines have a deep red coloration, then turn white with age. The flower is small, creamy-yellow, with red stripes. It is in a small bonsai dish (4 inches x 6 inches)/(10 cm x 15 cm). Since it was found at a local nursery, I would suspect that it is common in cultivation, but I have yet to see a photo of anything similar that I could use for an identification.
I was about 80% sure it was a Mammillaria, but the species ID appears to be more difficult. I have yet to find one with the correct combination of growth habit, spine color, and flower color. I was thinking since this plant likely came from a wholesale nursery that it was rather common in cultivation. Perhaps, I may be wrong. Addendum: Found it! Mammillaria marcosii http://www.cactus-art.biz/schede/MA...Mammillaria_marcosii/Mammillaria_marcosii.htm
Your plant doesn't look like Mammillaria marcosii at all. It doesn't have any hooked spines. Your plant is the far more common Mammillaria voburnensis.
That sure does look like it, but you are a flower away from being sure. Seriously Mammilaria is one genus with way too many species and not enough clarity on which are species and subspecies and such. One site worth its weight in gold is Mammilarias.net, here's a link to the page for M. marcosii: http://mammillarias.net/gallery/mammillaria_species.php?searchstring=marcosii&lg=uk Another is Norm Dennis' gallery of Mamms: http://www.tucsoncactus.org/cgi-bin/MySQLdb/DisplayCollection.php?Collection=Gallery5 But the description from Mamms.net is a good one to see if you meet it.
Good observation! It seemed a little odd that a wholesale nursery would be distributing a relatively rare cactus like a M. marcosii. Mine has such a deep red color to the spines that I had ruled M. voburnensis out based upon that characteristic alone. I should have been a little more observant. Didn't I get you on a Pachypodium ID a while ago? Touche'! ; ) Thanks Steve!
