Editing Pinus edulis (section)

== Taxonomy ==
{{unreferenced section|date=December 2019}}

Colorado pinyon was described by [[George Engelmann]] in 1848 from collections made near [[Santa Fe, New Mexico]] on [[Alexander William Doniphan]]'s expedition to northern Mexico in 1846 and 1847.<ref name="POWO" />
<ref>{{cite book |last1=Engelmann |first1=George |author-link1=George Engelmann |editor-last1=Wislizenus |editor-first1=F.A. |editor-link1=Friedrich Adolph Wislizenus |date=1848 |chapter=Botanical Appendix |script-chapter= |trans-chapter= |chapter-url= |chapter-url-access= |chapter-format= |title=Memoir of a Tour to Northern Mexico :Connected with Col. Doniphan's Expedition, in 1846 and 1847 |url=https://www.biodiversitylibrary.org/item/91630#page/88 |language=en |edition=First |location=Washington, D.C. |publisher=Tippin & Streeper |page=88 |doi=10.5962/bhl.title.41509 |doi-access=free |access-date=20 November 2024}}</ref>

It is most closely related to the [[single-leaf pinyon]], which [[Hybrid (biology)|hybridises]] with it occasionally where their ranges meet in western Arizona and Utah. It is also closely related to the [[Texas pinyon]], but is separated from it by a gap of about {{convert|100|km|mi}} so does not hybridise with it.

An isolated population of trees in the [[New York Mountains]] of southeast [[California]], previously thought to be Colorado pinyons, have recently been shown to be a two-needled variant of single-leaf pinyon from chemical and genetic evidence. Occasional two-needled pinyons in northern [[Baja California]], [[Mexico]] have sometimes been referred to Colorado pinyon in the past, but are now known to be hybrids between single-leaf pinyon and [[Parry pinyon]].