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.

Subalpine, alpine.  Meadows.  Summer.
American Basin, July 24, 2007 and Highland Mary Lakes Trail, July 21, 2010.

This is a fairly common Erigeron on rocky tundra.  It grows to just five inches tall yet has flower heads an inch across so it easily attracts your attention.  Look for it above tree-line on rocky outcrops.  The finely cut leaves and large flower heads are hallmarks.  It is found throughout the Colorado Rockies, in three northern counties in New Mexico, and is rare in just two southern counties in Wyoming. 

The plant was most likely first collected on the Wheeler Exploring Expedition of 1873-1875 by Franz Wolf (1841-1924) and Dr. Joseph Rothrock (1839-1922, surgeon and botanist with the Wheeler Expedition, Professor of Botany at the University of Pennsylvania, and considered the father of Pennsylvania forestry).  In 1880 Asa Gray named this plant Erigeron compositus var. pinnatisectus.  In 1899 Aven Nelson renamed it Erigeron pinnatisectus.

Subalpine, alpine.  Meadows.  Summer.
American Basin, July 24, 2007.

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 pinnatisectus