Hi! So I was wondering if you could ID these two cuties for me. I got them the other day, but I noticed that the tops of the spines turning brown. I was wondering if this is normal. Also, on each, the very top spines seem to have turned yellow a bit from the bottom. I did transplant them to new, slightly bigger clay pots also as soon as I got them (don’t know if that would be contributing to this). Thanks!
Those are Stetsonia coryne and Mammillaria decipiens. The brown tip of the spine is totally normal and just how spines develop. Spines start their development as living modified vascular tissue and then the cells that compose them begin to be lignified (turned to wood) and dry up, starting from the tip of the spine. You tend to only be able to observe this in very long-spined species like S. coryne. I think it’s pretty cool. :) It also means the spines aren’t firmly attached to the plant yet and can easily be knocked off.