Color can range from chocolate brown to olive green. Mature plant is 5 to 15 meters long, with flattened branches densely covered distichously with broad to linear blades and pneumatocysts. The holdfast can grow to 25 cm, the flattened stipe is usually 1 to 3.5 cm broad, and the branches arise within 1 meter of base. The stipe is smooth, but can be coveredwith tubercles. Blades stipitate at base, are elongated and round, and can reach 8 cm long. They too can have tubercles. Pneumatocysts are ellipsoid to subspherical and may or may not have papillae. Sporophylls vary from smooth, spatulate, or slender to wrinkled and flattened with sterile ridges. Sporophylls are shorter and narrower than average blade. Closeup:Newly recruited plants, mature stipe with blades and tubercules. SAMPLING CODE NOTES: EGBL = Blade; EGHO = Holdfast; EGME = Adult, > 1 m from base of stipe to end of rachis; EGMR = Recruit < 1 m from base of stipe to end of rachis; EGTH = Thallus, no longer used.

Fertile all year, but mostly between April and November. Forms continuous belts in intertidal and is often mixed with Macrocystis in deeper water. Morphological variability is associatedwith geographic location. Northern populations have tuberculate stipe

Midtidal to subtidal 20 m; British Columbia, Canada to Baja California, Mexico.