The seed cones are globose to oblong, 15–33 mm long, with 6 or 8 (rarely 4 or 10) scales, green at first, maturing gray or gray-brown about 20–24 months after pollination.

The cones remain closed for many years, only opening after the bearing branch is killed (in a wildfire or otherwise), allowing the seeds to colonize the bare ground exposed by the fire.

[3][5] This description was soon after disputed by Maxwell T. Masters who, in 1896, published a journal article where he said it should be considered a subspecies of Cupressus benthamii with the variety name of arizonica.

[3][6] The remaining four are listed as separate species: Hesperocyparis arizonica is found mainly in northern Mexico in the states of Chihuahua, Coahuila, Durango, Tamaulipas, and Zacatecas.

An example occurrence is within the Sierra Juárez and San Pedro Mártir pine–oak forests of Mexico,[15] where it is found along with canyon live oak and California fan palm.

Close taxonomic relatedness, in turn, offers both challenges and opportunities if and when assisted migration is considered as a mode of climate adaptation to prevent extinctions of endemic cypresses in the American southwest.