Anthopleura xanthogrammica

[4] The crown of tentacles can be as wide as 25 cm in diameter,[4] while the column, itself, tends to be widest at the base in order to offer a more stable connection to the rocks.

[5] Generally, A. xanthogrammica is found along the low to mid intertidal zones of the Pacific Ocean, from Alaska to southern California and sometimes downwards to Panama, where cold water swells can occur.

[3] Occasionally A. xanthogrammica can also be found in deep channels of more exposed rocky shores and concrete pilings in bays and harbors.

[5] Anthopleura xanthogrammica anemones living in caves and shady zones have reduced or no natural symbionts and tend to be less colorful.

[4][7] The anemone feeds on sea urchins, small fish, and crabs, but detached mussels seem to be the main food source.

Occasionally, A. xanthogrammica can be confused with large individuals of A. elegantissima or A. sola, but both of these other anemones have (usually) pink-tipped tentacles and a striped oral disk, unlike A.xanthogrammica.

Spectacular lineup of Giant Greens at Hazard Reef, Montana de Oro State Park . Channel is about a foot (30cm) wide. It drains a large tidepool which supplies abundant good food.
Giant Greens at New England Aquarium
Giant Greens at Yaquina Head Outstanding Natural Area , Oregon.