Semi-desert, foothills. Openings, woodlands. Late spring, early summer.
Arches National Park, Utah, May 4, 2005.

This is a very common and lovely plant of dry open lowlands.  It is often found in sand and gravel soils, commonly on rim rock, and commonly in Pinyon/Juniper forests.  Its circular growth pattern; bright green, thin, vertical leaves; dried old leaves; and abundant cheerful flowers make it easy to identify.  As plants age, they grow outward in a ring, slowly expanding the ring over the years.  It is common for the inner part of the ring to have died and then woody roots and stems are exposed.  I have seen plants six feet in diameter and these must be many decades or even centuries old.

Thomas Nuttall collected the first specimen of this plant for science along the headwaters of the Platte River on his trip to the Pacific with the Wyeth Expedition of 1834-1837.  He named the plant Stenotus armerioides.  Asa Gray renamed it Aplopappus armerioides in 1884, Kuntze renamed it Aster armerioides in 1891, and Welsh renamed it Haplopappus armerioides in 1983.

"Stenos" is Greek for "narrow", referring to the leaves.  "Armerioides" is Latin for "similar to Armeria", probably a genus of Dianthus flowers.

Semi-desert, foothills. Openings, woodlands. Late spring, early summer.
Canyon of the Ancients National Monument, April 25, 2007.

Stenotus armerioides is often the dominant wildflower species in the gravels of canyon rims at about 6,500 feet.  Notice the dead tufts of leaves at the base of the bright green plants and also notice the exposed roots of dead plants in the foreground.

Semi-desert, foothills. Openings, woodlands. Late spring, early summer.
McElmo Canyon, Canyon of the Ancients National Monument, April 27, 2005.

Semi-desert, foothills. Openings, woodlands. Late spring, early summer.
McElmo Canyon, Canyon of the Ancients National Monument, April 27, 2005.

Flowers are very showy golden and buds are waxy.