Hole in the top of my discocactus?
I work at a nursery and snagged this cactus as it came off the truck yesterday. I think it is a Discocactus buenekeri, but I'm not sure. It is in a 4-inch pot and has about fifteen babies.
I'm concerned about the hole in the top of the mother plant. Is this normal? Is it getting ready to make its cephalium? The mother plant is definitely lighter in color than the babies. I looked down the hole with a flashlight...couldn't see much. None of the babies have holes.
Any advice would be much appreciated. I'm new to growing cacti, but the collection is already getting out of control! Thank you.
Here is a link that might be useful: Discocactus hole?