Dichotomous Key/Dioon

Dioon_edule01.jpg Dioon edule Plantae Cycadophyta Cycadopsida Cycadales Zamiaceae Dioon Key to the species of Dioon: 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.