Laramie Chickensage

Laramie false sagebrush (Sphaeromeria simplex, synonym Tanacetum simplex) is a mat-forming perennial herb or shrub in the Asteraceae family. Growing less than 10 cm tall, the silver-hairy linear leaves are crowded at the base of the stem and are entire or 2-3 toothed at the tip. Flowering stems have 2-3 small, linear leaves and a single, terminal flower head of numerous, yellow disk flowers (ray flowers are absent). It flowers/fruits from May to August Laramie false sagebrush is endemic to southeast Wyoming in North America. It occurs primarily on gentle slopes or rims of dry, rocky limestone-sandstone "pebble plains" in wind-scoured openings dominated by cushion plant communities within more densely vegetated juniper, limber pine, big sagebrush, or mountain mahogany stands. Occasional high elevation populations occur on thin-soiled outcrops of limestone bedrock associated with red beds in cushion plant/Artemisia tripartita var. rupicola communities. Elevation ranges from 7200-8760 feet.

Sphaeromeria simplex (A. Nelson) A. Heller, Muhlenbergia 1: 7. 1900.
Tanacelum simplex A. Nelson, Bull. Torrey Club 26; 484. 1899.
A tufted perennial, with a short cespitose woody caudex; stems about 1 dm. high, silkycanescent; leaves crowded at the base, closely and finely silky-canescent, simple and linear, 2-4 cm. long, 1-2 mm. wide, or bifid or trifid at the apex; stem-leaves few and linear, entire; heads solitary at the end of the stems; involucre 5-6 mm. high, 8-10 mm. broad; bracts about 25, in two series, light-yellow with green midrib, shining, silky, oval or obovate, or the outer ovate-lanceolate; ray-flowers few; corollas 3-4-lobed, lance-ovoid, 3 mm. long; disk-corollas campanulate with a short tube, glabrous, 3-3.5 mm. long; achenes about 2 mm. long, truncate at the apex.
Type locality: Near Laramie, Wyoming. Distribution: Wyoming.

Sphaeromeria simplex is a species of flowering plant in the aster family known by the common names Laramie chickensage and Laramie false sagebrush. It is endemic to Wyoming in the United States.

This small perennial herb forms clumps a few centimeters tall. The leaves are divided into many lobes. The flower heads contain many yellow disc florets and no ray florets. Flowering occurs in May through August.

This plant grows on exposed limestone substrates among other cushionlike plants and some larger plants such as sagebrush. There are 11 occurrences of the plant, most of which have been discovered since 1997.