What the strange growth on the top of your cycad is

Cycads, like this dioon edule, may look like small palm trees, but they are not even related to them. They are related, believe it or not, to pine trees. And it isn't until you see one start to produce cones that it even makes any sense. Once you see it, it does.

If you are seeing a strange growth like this on any species of cycad, including the common "sago palm", you are seeing the plant that is mature enough to begin its reproductive cycle. And since it can take over twenty years for a cycad to cone, many people never see this at all. It's a sign of a robustly healthy plant, and it's kind'a cool to see.

Even mature plants, like this one, don't cone every year. This one has coned three times since I've had it, but it usually pushes out a flush of leaves instead. The really, really, mature ones can do both cone AND push out a flush of leaves. I guess this one is still too young for that.

Male cones of Dioon edule cycad.

Cycads are dioecious, that is, each plant is either male or female. Most plants, of course, aren't. And so in order for viable seeds to be produced, a male plant (you can tell by the shape of the cones that this one is a male) needs to be in close proximity to a female plant that is coning at exactly the same time. You should now get a good idea why these plants are so rare in the wild. Not a terribly efficient system for life to find a way!

After the cones start to open up, they will start breaking up and looking brown and ratty. They will break off easily, and should be disposed of. The pollen inside is toxic, but only if you eat it. Still, it's a good idea to wear gloves when handling a cone, and wash your hands.