18" (46 cm) high, 9" (23 cm) wide. Smooth. Reddish- to olive-brown or lighter, to cream-colored and white; paler forms may be mottled. Oral disk lobed; tentacles slender and very abundant, 1000 in large specimens, producing a frilled appearance. Long, white threads of stinging cells discharged when animal is disturbed.
Attached to rocks, wharf piles, and other solid objects; near low-tide line and below in shallow water.
Arctic to Delaware; Alaska to s. California.
These anemones reproduce either sexually or, asexually, by dividing lengthwise or by leaving behind, as they creep over surface, bits of tissue from the pedal disk that regenerate into complete anemones.