Editing Picea engelmannii (section)

== Subspecies and hybrids ==
[[File:Engelmann spruce below Boulder Pond Payette NF.jpg|thumb|Forest floor under Engelmann spruces]]
Two geographical subspecies (treated as [[Variety (botany)|varieties]] by some authors, and as distinct species by others) occur:
*''Picea engelmannii'' subsp. ''engelmannii'' ('''Engelmann spruce'''). All of the range except as below.
*''Picea engelmannii'' subsp. ''mexicana'' ('''Mexican spruce'''). Two isolated populations on high mountains in northern Mexico, on the Sierra del Carmen in [[Coahuila]] ([[Sierra Madre Oriental]]) and on [[Cerro Mohinora]] in [[Chihuahua (state)|Chihuahua]] ([[Sierra Madre Occidental]]). Engelmann spruces of the [[Madrean sky islands]] mountains in the extreme southeast of Arizona and southwest of New Mexico also probably belong to this subspecies, though this is disputed.

The Engelmann spruce [[Hybrid (biology)|hybridises]] and [[Intergradation|intergrades]] extensively with the closely related [[Picea glauca|white spruce]]<ref name=":02" /> (forming a species complex known as ''[[Picea × albertiana]]''; Alberta spruce, or interior spruce) in interior Canada, and to a lesser extent with the closely related [[Picea sitchensis|Sitka spruce]] where they meet on the western fringes of the Cascades.