What is Wrong with this Cactus?
Yesterday, I went to a small nursery that has a greenhouse with some gorgeous houseplants in it. They had some cacti and I couldn't resist picking a few up since they were larger cacti and only cost $3.99.
Today, I repotted the ones that I bought as they were much too large for the small 4 inch pots that they were in - roots were coming out of the bottom, etc.
When repotting one of them, I noticed something that I didn't see at the nursery. What is along the bottom of the cactus? It is dry and does not appear to be soft. Is it rot or sunburn? What can I do for it?
Any help is appreciated.