Eucephalus glaucescens is a North American species of flowering plant in the aster family known by the common name Klickitat aster. It grows on rocky slopes and in subalpine meadows at high elevations on and near Mt. Adams in the south-central part of the US State of Washington. Eucephalus glaucescens is a perennial herb up to 160 cm (5 1⁄3 ft) tall, with a woody caudex. Stems are hairless. Leaves are whitish and waxy. One plant will usually produce 5-60 flower heads in a large array. Each head has 8-13 purple ray florets surrounding numerous yellow disc florets.