Astonishingly, the Alaria fistulosa averages 40 feet in length but only six and a half pounds in weight. This kelp has large leaves with a hollow stem interspersed by bulbs that allow it to float. It houses its reproductive system in comparatively small and thick leaves near its base. It is a relative of the Alaria esculenta, found in Europe.
Laminaria setchellii are brown kelp that resemble a fluted fan when submersed in water. They are found on rocks and have thick leaves that can grow nearly three feet long. Beachcombers commonly see them on rocks when the tide recedes, where they may grow so thickly that they obscure the rocks themselves.
The Thalassiophyllum clathrus is a fan-shaped plant. As it develops, it grows enormous leaves that twist shut in a manner reminiscent of lettuce, but during its maturation, its leaves gradually separate down the center until only a single leaf remains. Upon maturity, its leaves spread wide. It retains a small vestigial leaf near its base, but otherwise is composed of a stem and a single, large leaf.
Scientists only discovered the Aureophycus alueticus in 2007. This species grows up to nine feet long, has a dark yellow trunk, and graceful, flowing leaves. In comparison to other varieties of kelp, it is especially solidly anchored to surrounding rocks. This allows it to survive the especially powerful waves found near Kagamil Island in the Aleutian Island chain, where it was discovered.
