Erigerons, commonly called "Daisies" or "Fleabanes", are a large and complex genus with over 173 species in North America.  This website shows 28 of the 48 species in the Four Corners area. (Other large genera in North America are Astragalus (350 species, 31 on this website), Penstemon (250 species, 22 on this website), and Eriogonum (250 species, 16 on this website).

    Some Erigerons are annuals, some biennials, most are perennials.

    Erigerons have numerous quite small tubular disk flowers. Such minute disk flowers are typical of most Asteraceae, but most Erigerons are distinctive in also having minute, very narrow (~1 millimeter wide) ray flowers (which are also distinctively very numerous).    

    Almost all Erigerons have disk and ray flowers; a few Erigerons (some in our area) have only disk flowers.

    Disk flowers are almost always yellow and ray flowers are white or very pale blue/purple or pale pink. In North America, but not in the Four Corners region, there are a few Erigerons with yellow ray flowers.

    Erigeron disk flowers are bisexual and fertile and the ray flowers are pistillate and fertile.

    Phyllaries are almost always about the same height but vary in width, hairiness, and color. 

    Erigerons grow from the semi-desert to the alpine and although a few are uncommon, most are quite 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.

Montane to alpine.  Meadows, openings.  Summer.
Cinnamon Pass, August 1, 2007 and Colorado Trail near Stony Pass, July 21, 2011.

This lovely Daisy is, in the words of Intermountain Flora, "a common and highly variable ... species", but it is quite distinct from other Erigerons, especially because of its deeply divided basal leaves.  E. compositus is primarily apomictic, i.e., it reproduces not by pollination of ovules but by parthenogenesis (Greek for "virgin birth").  Ovules develop into new life without being fertilized.  This accounts for the uniformity of characteristics in local populations.  Distant populations do differ, however, especially in pubescence and ray flower petal length. 

Rayless forms are common according to Colorado plant authority, William Weber.  Both forms grow from two to ten inches tall; both plants in the photographs at left are six inches tall. 

E. compositus enjoys rocky openings and can be found through most higher elevations, but in the Four Corners area (only in Colorado and Utah) it is chiefly found from high montane to alpine.  As is true for almost all of the blue Erigerons, the color of E. compositus ray flowers varies from white to blue to pink. As noted above, Erigeron disk flowers are yellow. 

Frederick Pursh named this species in 1814 from a specimen collected by Meriwether Lewis in 1806 near Kooskooskie, Washington.

Click to see more Erigeron compositus.

Montane to alpine.  Meadows, openings.  Summer.
Cinnamon Pass, August 1, 2007.

Montane to alpine.  Meadows, openings.  Summer.
Cinnamon Pass, August 1, 2007.