Allium macropetalum

Arizona Onion - Allium macropetalum
East of Hillsboro, NM, USA
March 30, 2017

The Arizona Onion, Allium macropetalum, pictured here was one of several species we saw in a small area on a walk in late March 2017.

As shown on the BONAP map to the right, the range of this species in the United States is limited to Arizona, Utah, Colorado, New Mexico, and Texas (which considers it a noxious weed).  The light green color indicates that the species is native to and not rare within the county indicated.  It is also found in Sonora, Mexico.

This species is also known as Largeflower Onion, Large-petal Onion, Desert Onion, and Desert Onion Lily.  Scientific synonyms include Allium deserticola (see Flora of New Mexico, Volume 19, p. 142 by Elmer Ottis Wooton and Paul Carpenter Standley) and Allium reticulatum.  The current description of this species was made by Per Axel Rydberg, in 1904, from a specimen collected in Colorado by C. S. Crandall on 14 May 1898. 

The Largeflower Onion, Allium macropetalum, was especially common in the Ready Pay Gulch area east of Hillsboro in early April 2014.   In A. macropetalum the fiber covering which surrounds the bulb is interlaced (as in A. geyeri and A. textile).  This is different from most other Allium species, species which typically have non-fibrous coverings or the fibers are parallel (not woven).  This species typically blooms in March and April.

The Navajo used this onion as a food source.  The growth pattern of the root fibers which cover the bulb is often useful in identifying onions to species, see Southwest Colorado Wildflowers, for an image.


Immediately above, Ready Pay Gulch, East of Hillsboro, NM - April 9, 2014

Photograph immediately above and four below
North Wicks Canyon, E of Hillsboro, New Mexico
April 5, 2020

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