Fucus serratus, the toothed wrack, is a robust, olive-brown shrubby seaweed that grows in high densities low on the seashore. The fronds are about 2 cm wide, splitting in two repeatedly. The fronds bear no air bladders. The whole plant typically grows to about 60 cm long. The fronds have a serrated edge and grow from a short stalk.Also known as serrated or saw wrack. Ripe male plants can be distinguished by their orange colour.