Laramie chickensage

Tanacetum simplex A. Nelson, Bull. Torrey Bot. Club 26: 484. 1899

Perennials, 1.5–2.5(–8) cm (cespitose, bases sometimes woody). Stems erect to decumbent, sericeous. Leaves mostly basal; blades (15–30 × 1.5–8 mm) pinnati-palmately lobed (lobes 2–3, linear, 1–2 mm wide) or linear, faces silvery-canescent. Heads borne singly. Involucres 4.5–7 mm. Phyllaries (12–)14–20+, midribs canescent or glabrous. Cypselae (light brown) 1.8–2.5 mm (faces finely striate).

Flowering May–Aug. Dry hills and slopes; of conservation concern; 2200–2700 m; Wyo.

Sphaeromeria simplex is in the Center for Plant Conservation’s National Collection of Endangered Plants.