Silver chickensage, Nuttall’s false sagebrush

Tanacetum nuttallii Torrey & A. Gray

Perennials, 5–20 cm (cespitose). Stems erect, canescent. Leaves mostly basal; blades (± cuneate, 7–15 mm) entire or apices 3(–5)-toothed or -lobed, faces silvery-canescent. Heads usually 2–7 in subcapitate to corymbiform arrays (1–1.5 cm across), sometimes borne singly. Phyllaries 12–16, sparsely tomentose. Involucres 3–5(–7) mm. Cypselae 2–2.5 mm (3–5-ribbed, apices with thickened rims, faces glabrous or sparsely gland-dotted). 2n = 18.

Flowering Jun–Jul. Dry hills; 2000–2600 m; Colo., Idaho, Nev., Wyo.

Sphaeromeria argentea is moderately tolerant of alkali.