Dictyota dichotoma is a brown alga with a flattened membranous thallus. Fronds regular dichotomous in form, olive-green to yellowish brown in colour with a slight blue iridescence when immersed. Sample 14.5 x 17 cm, parallel margin blades, absent central vein, texture delicate, constant width (~1cm). It is branched, colourless and attached by colourless rhizoids; branched with rounded or bifid tips. These sporangia are dispersed. Small dark spots. It is a seasonal dioecious species producing diterpenes and it is home to small invertebrates. Occurs in tufts on rocks in tide pools and shallow subtidal areas.