It is found in Tomellín Canyon and the eastern branches of La Cañada de Cuicatlán.

[6] Dioon purpusii grows about 5 meters high or taller, with a dbh about 40 cm being typical.

The leaflets are arranged along the somewhat flattened rachis in matching symmetrical pairs without alteration.

The first five to twenty centimeters (depending on the overall length of the leaf) are fully formed leaflets, which are straightly lanceolate with flat, dentate margins; those growing towards and at the end of the rachis reduce to mere spines.

The green or pallidly brown pollen cones (male) are long (20–30 cm.

Mostly they grow on the steep rocky slopes of deep gorges together with cacti, agaves and Beaucarnea in 1000 to 1500 meters sea level.

Sites and plants are hardly disturbed, the local population uses the leaves only on Palm Sunday.