Taproots penetrating to 20-25+ cm. Stems hollow. Leaf blades 4-25 × 1-6 cm. Peduncles 3-15 mm. Involucres 8-15 mm. Disc florets slightly exserted from involucres; corollas: tubes 3.5 mm, throats 2.5 mm, lobes 2-3(-3.5) mm. Cypselae 6-7 mm; pappi 5 mm.

Flowering Jun(-Aug). Barren, white silty-clay; of conservation concern; 2000 m; Wyo.

Yermo xanthocephalus is known only from one site in central Wyoming. It is in the Center for Plant Conservation´s National Collection of Endangered Plants.