1a. Adult thallus has long fronds of 20-30m consisting of a stipe and large blades( m) grow at intervals. The blade is formed with a pneumatocyst at the base and end in a point. These species form kelp beds...............................2
1b. Adult thallus is relatively smaller (1-5m) consisting of a thick rubbery stipe with large crowning sporophylls or stipe differentials into a rachis with numerous small blades along the edges. Found in the lower intertidal to the upper tidal......................................................3
2a. Holdfast is pyramidal shaped and branches dichotomously. Found in depths of 20-30m in the subtidal zone....................................Macrocystis pyrifera
2b. Holdfast creeps laterally along and is branched randomly from........................Macrocystis integrifolia
3a. Thallus consists of a thick rubbery stipe (1-2m) that dichotomously branches as a wishbone shaped blade. Long sporophylls crown from each apex the blade.......................................Eisenia Aroborea
3b. Stipe is thick and flattened with numerous small blades along its edges. Blades can differentiate into sporophytes which are small shriveled blades or pneumatocysts..............................Egregia menziesii
