Eucephalus glabratus is a North American species of flowering plant in the family Asteraceae with the common names of smooth aster[3], smooth wayside-aster,[1] and Siskiyou aster.

[4] It is a perennial herb up to 60 centimeters (24 inches) tall, with branching rhizomes.

One plant will usually produce 3–8 flower heads per stem.

[5] Eucephalus glabratus grows at elevations of 700–2,300 meters (2,300–7,550 feet) in openings in oak and conifer forests or chaparral[5] of the Klamath Mountains[6] of southwestern Oregon and northwestern California.

[7] NatureServe classifies Eucephalus glabratus as Apparently Secure (G4) globally and Vulnerable (S3) in California.