Dioon dioecious shrubs, with cylindrical stem, usually with many leaves and petioles they are persistent or deciduous.
The genre is often divided into two groups of different morphology.
Enel first group: D. mejiae, D. rzedowskii, D. spinulosum, “usually characterized by large fronds, well developed trunks, and massive cones”.
Elsegundo group contains : D. califanoi, D. caputoi, D. edule, D. holmgrenii, D. merolae, D. purpusii, D. sonorense, D. tomasellii, and they are “less robust, with generally less large trunks, considerably lower fronds, and smaller cones” (Norstog & Nichols 1997).
Hojas pinnadass, spirally arranged, Leaflets with unarticulated; and low leaflets often reduced to thorns.
Distribution and habitat
Surango distribution in Mexico is consistent with the distribution of the Sierra Madre.