This blog is about growing tropical-looking plants in the Phoenix, Arizona area



July 24, 2013

Double coning Dioon edule cycad

Even though they look like they should be related to palm trees, cycads, like this dioon edule, are more closely related to pine trees. And like pine trees, they cone.

Cycads are a very ancient type of plant that hasn't really changed much since the days of the dinosaurs. In addition to not having a flower (flowering plants hadn't evolved yet), it is dioecious, that is, there are male and female plants. And since most plants do flower, and most have both male and female parts on the same plant, it has given them an advantage over more primitive plants.

This particular cycad in my garden is a coning male. Yes, you can tell the sex (gender) of a cycad by the shape of its cone. And in order for there to be more baby cycads from this daddy, there would have to be a female coning at exactly the same time. You can see the evolutionary disadvantage of being a dioecious plant!

This lonely guy has coned three times since I've had him, but I've never seen a double cone before. It's interesting to cycad collectors, who like to show off this kind of stuff, but personally, I am always disappointed when I see a cone as I know that there will not be a flush of leaves that season. I am not growing this cycad for botanical interest, I am growing it for the tropical effect.

Anyway, if you see one of these on your cycad, such as a "sago palm", don't worry, it's perfectly natural. It will grow for a couple of weeks, then begin to fall apart. Simply dispose of it when it starts to look ratty.
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