Fucus gardneri is olive brown in colour and similar to Fucus spiralis. It grows to long and branches somewhat irregularly dichotomous and is attached, generally to rock, by a discoid holdfast. It has airsacks at the top.
The tips of mature individuals swell up and provide flotation for the plant as well as reproductive chambers for developing sperm and eggs. During low tide, the swollen tips dry up squeezing out sperm and eggs which unite into a zygote during the next flood tide and settle onto a substratum.
Native Americanshistorically harvested the dried swollen tips of Fucus gardneri – sometimes referred to as "Indian pop corn". When the airbubbles are popped, it secretes a thick lotion, very moisturizing.