Pleurophycus gardneri Setchell & Saunders ex Tilden (BC)

This species can be locally common and is distinct for its thick and wide central midrib (Image A). This is a simple kelp consisting of a hapteral holdfast, stipe and simple blade, which again is distinguished by the strong central midrib (Image B).

This species is widely distributed along the coast of BC, from the lowest intertidal to subtidal (13 m for our deepest collection). There is a slight chance that juveniles can be confused between Pleurophycus gardneri Setchell & Saunders ex Tilden and Pterygophora californica Ruprecht, but the midrib is much less developed in the latter species. Alaria marginata Postels & Ruprecht also has a thick midrib, but it is much narrower and eventually sporophylls develop from the stipe. Anomalies abound in nature and an individual presumably growing epiphytically on another should not be interpreted as branching (Image C) as kelp gametophytes are known to epiphytize kelp sporophytes for both their own and other species (Lane & Saunders 2005).

Image A. Individuals from the low intertidal Gordon Islands (West), Gwaii Haanas, BC (EGWS000190).

Image B. Specimen displaying the hapteral holdfast, stipe and simple blade as is characteristic of this species (subtidal (13 m) on rock, Tcenakun Point, Chaatl Island, Haida Gwaii, BC; GWS012544).

Image C. An individual of Pleurophycus gardneri Setchell & Saunders ex Tilden growing on another (subtidal (11 m ) on rock, Bamfield, Seapool Rock, BC; GWS003061).