Iris missouriensis

Rocky Mountain IrisIris missouriensis
McKnight Cabin
Black Range, New Mexico, USA

In early June, Rocky Mountain Iris, Iris missouriensis, is in bloom at McKnight Cabin and along Trail 79 to McKnight Mountain near the ridge crest of the Black Range.  We have seen them at various points along the Black Range Crest Trail (Trail 79) over the years, most notably at McKnight Cabin and near Sawyer’s Peak, also on Trail 79.  I prefer this type of Iris to the large flag type which is so prevalently domesticated.  

This species is found throughout western North America, from the western provinces of Canada and the western states of the United States, into northern Mexico. (See BONAP map to the right, light green indicates that the species is native to the county.)  It grows at a wide range of elevations, from 30 feet to 9,000 feet.  I suspect that it might even grow at sea level and we found it above 9,000 feet at McKnight Cabin.  It prefers very wet conditions prior to bloom and very dry thereafter.   From the Flora of North America:  “The ecological range of Iris missouriensis is probably more varied than that of any other North American species of the genus, extending from almost sea level in southern California to 3000 m in Montana and Wyoming. There is correspondingly wide variation in a number of characters, which has caused much confusion as to taxonomic circumscription.”  As a result, it has a number of synonyms, including; Iris arizonica, Iris longipetala, Iris montana, Iris pariensis, Iris pelogonus, and Iris tolmiena. 

The species was first described by Thomas Nuttall in 1834  from a specimen collected by Wyeth in 1833.

Sawyers Peak Trail, Black Range, New Mexico
June 30, 2019
Photographs immediately above and below

Grandview Trail, Black Range, New Mexico
October 2, 2020

© Robert Barnes 2018-2023