Milbert's Tortoiseshell

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    Erigerons, commonly called "Daisies" or "Fleabanes", are a large and complex genus.  This web site shows more than half of the 48 species in the Four Corners area;  there are 130 species in North America and 200 world-wide.

     Erigerons have yellow disk flowers and numerous narrow ray flowers that are white, pink, or purple (but not yellow).  They grow from the semi-desert to the subalpine regions and although a few are uncommon, most are very common.

      In 1753 Linnaeus gave the genus its name from the Greek "eri" ("early") + "geron" ("old man", as in "geriatrics", the study of old age processes and problems).  Perhaps the Greek name refers to characteristics of some now unknown plant or perhaps it refers to the early flowering of many species and to the bristly pappus of the developing seed, or perhaps to the puffy, grizzled appearance of the mature seed head.

Erigeron glacialis

Erigeron glacialis

A Rocky Mountain Parnassian Butterfly (Parnassius smintheus) feeds on Erigeron glacialis while a Milbert's Tortoiseshell (Nymphalis milberti) sun's itself on the ground.
Erigeron glacialis
Erigeron glacialis
Erigeron glacialis. Synonym: Erigeron peregrinus.  (Glacial Daisy)
Asteraceae (Sunflower Family)

Montane, subalpine.  Meadows.  Summer.
Sharkstooth Trail, July 14, 2006, La Plata Canyon, July 18, 2006, and Winter Trail, July 10, 2009.

Erigeron glacialis is found in middle and high mountain meadows and open forests.  It has flowers that range from very light lavender (almost white sometimes) to deeper lavender or pink/purple. 

The photograph below shows two flowers on the same plant and indicates how much ray flower length, width, and color depend on the maturity of the flower.

Erigeron glacialis

E. glacialis is most quickly distinguished from other Erigerons by its 2-3 millimeter wide ray flowers, twice as wide as those of other ErigeronsE. glacialis possesses another unusual characteristic: it spreads from underground roots and often sends up hundreds of basal leaf rosettes.  These rosettes are hard to distinguish from those of Oreochrysum parryi.  A small percent of the rosettes of these two plants send up flowering stems.
   

Erigeron glacialis

Erigeron glacialis

Erigeron glacialis

Erigeron glacialis. Synonym: Erigeron peregrinus.  (Glacial Daisy)
Asteraceae (Sunflower Family)

Montane, subalpine.  Meadows.  Summer.
Sharkstooth Trail, July 14, 2006.

Erigeron glacialis stems below the phyllaries have numerous, fine, long, white hairs.

Erigeron glacialis phyllary tips are red-tinged (to varying degrees) and they have short, fine, red-tipped glandular (sticky) hairs (the tiny dots edging the phyllaries, most easily seen in the top photograph at left).  The glandularity not only sets E. glacialis apart from a number of other Erigerons, it also separates E. glacialis from E. peregrinus, with which it was for many years mistaken by professional botanists. 

Range also separates E. glacialis and E. peregrinus: E. peregrinus was discovered in Unalaschka and E. glacialis was discovered in Wyoming.  The two species overlap in range from the Pacific Northwest into Alaska, but south and east from there into Montana and New Mexico (see the range map below), is Erigeron glacialis territory.

Both species were discovered early in the 19th century:  D. Nelson collected a plant in Unalaschka (in the Aleutian Islands) in the first years of the 19th century and it was named Aster peregrinus by Joseph Banks in Frederick Pursh's 1814 Flora Americae SeptentrionalisIn 1897 Edward Greene renamed this plant Erigeron peregrinus. In 1841 Thomas Nuttall gave the name Aster glacialis to a plant he collected in Wyoming in the 1834); in 1904 Aven Nelson renamed this plant Erigeron glacialis.

"Peregrinus" means "wandering". "Glaci" is Latin for "ice". Nuttall was probably indicating that the plant he collected was growing in cold, icy, conditions. 

Erigeron glacialis

Erigeron glacialis

Erigeron glacialis

Erigeron glacialis.  Synonym: Erigeron peregrinus.  (Glacial Daisy).
Asteraceae (Sunflower Family)

Montane, subalpine.  Meadows.  Summer.
Lone Cone, Upper Calico Trail, August 9, 2011 and July 31, 2013;
Lake Hope Trail, August 11, 2014.

E. glacialis commonly is found in patches of dozens or even hundreds of plants.

When ray flowers fade, they curve downward and then inward toward the stem leaving just a hint of blue/pink showing.

Range map © John Kartesz,
Floristic Synthesis of North America

State Color Key

Species present in state and native
Species present in state and exotic
Species not present in state

County Color Key

Species present and not rare
Species present and rare
Species extirpated (historic)
Species extinct
Species noxious
Species exotic and present
Native species, but adventive in state
Eradicated
Questionable presence

Range map for Erigeron glacialis

Range map for Erigeron peregrinus