Flattened Acid Kelp (Desmarestia ligulata)

Description: Flattened acid kelp is named for its flat blades and high acid content. The blades branch several times with a faint midrib and each blade tapers to a point. The kelp comes in various shades of brown, sometimes with different branches of the same individual being different shades. The longest part of this algae can reach up to 80 cm long.

Habitat: This kelp lives on rocks in the low intertidal zone down to subtidal zones from semi-protected to semi-exposed areas. Flattened acid kelp can be found in many locations around the world. Along the west coast of North America it ranges from Alaska down to Baja California, Mexico.

Tide Pool Tidbits:

• This species secretes sulfuric acid. Because of its high acid content, it may cause other species that are kept in enclosed spaces with it (such as in tide pools) to quickly break down.

References: Seaweeds of Alaska, The New Beachcomber’s Guide to the Pacific Northwest by J Duane Sept