Noun | 1. | Fucaceae - small family of brown algae: gulfweeds; rockweeds protoctist family - any of the families of Protoctista Fucales, order Fucales - coextensive with the family Fucaceae fucoid algae, fucoid - any of various algae of the family Fucaceae rockweed - coarse brown seaweed growing on rocks exposed at low tide genus Fucus - type genus of the family Fucaceae: cartilaginous brown algae Ascophyllum, genus Ascophyllum - brown algae distinguished by compressed or inflated branchlets along the axis genus Sargassum - a genus of protoctist |