Dichotomous Key/Dioon

Key to the species of Dioon:

Dioon

Dioon edule
Kingdom	Plantae
Division	Cycadophyta
Class	Cycadopsida
Order	Cycadales
Family	Zamiaceae
Genus	Dioon
Information related to Dioon Wikipedia • Wikispecies • Wikicommons

Dioon

• DIO1: Leaflets straight
• DIO2: Leaflets curved or hooked

DIO1

• DIO3: Leaflets less than fifteen millimeters wide.
• DIO4: Leaflets over fifteen millimeters wide.

DIO2

• Dioon sonorense: Leaflets less than five millimeters wide.
• Dioon tomasellii: Leaflets over five millimeters wide.

DIO3

• Dioon edule: Leaflet edges entire.
• DIO5: Leaflet edges with spines

DIO4

• Dioon rzedowskii: Petiole without spines.
• DIO6: Spines present on petiole.

DIO5

• DIO7: Leaflets inserted at 90 degrees to rachis.
• DIO8: Leaflets inserted at 45 degrees or less to rachis.

DIO6

• Dioon mejiae: Leaflet edges entire.
• Dioon spinulosum: Leaflet edges with spines.

DIO7

• Dioon holmgrenii: Leaflets seven to nine millimeters wide; Leaflets do not overlap.
• Dioon merolae: Leaflets en to twelve millimeters wide; Leaflets overlap.

DIO8

• Dioon caputoi: Leaflets less than five millimeters wide; Leaflets flat and do not overlap.
• DIO9: Leaflets over five millimeters wide; Leaflets keeled and overlap.

DIO9

• Dioon califanoi: Leaflets seven to eight millimeters wide.
• Dioon purpusii: Leaflets eight to ten millimeters wide.