Intertidal Organisms EZ-ID GUIDES


on this species


Phyllospadix spp.(Surfgrass)

photo of surfgrass
Copyright © 2006 Mary Jo Adams


The easiest way to distinguish between surfgrass and eelgrass is to look at the habitat.  Surfgrass likes high energy areas where it is bonded to the rocks by tiny root hairs.  The roots and rhizomes may be covered by sand that has washed over it, but beneath that, their attachment will be to rock.  Eelgrass on the other hand prefers sheltered areas with soft substrate, mud or sand.

The leaf blades of surfgrass tend to be narrower than those of eelgrass.  Color is another clue as Phyllospadix is bright emerald green while eelgrass is a deep shade of green.

Belonging to the family Zosteraceae, three species of Phyllospadix can be found in low intertidal and subtidal zones on Pacific Northwest beaches.     P. serratula or serrated surfgrass has a range from Alaska to Washington.  Running your finger along the distal blade of this species, you will feel small serrations and may be able to see the uneven edge with the aid of a magnifying glass.  With a microscope you could observe that it has 5-7 leaf veins.   P. scouleri, commonly called Scouler’s surfgrass can be found from Alaska to California.  It has only 3 leaf veins.  Neither of these species exceeds a blade length of 3 feet.   P. torreyi, also known as Torrey’s surfgrass, grows from southern Vancouver Island to the Baja Peninsula and attains a blade length to 10 feet.  Its leaves are very narrow, only 2 mm wide.    (Note: P scouleri and P. serratula were once considered one species.)

The fruit from the inflorescence of Phyllospadix is flattened and somewhat heart shaped.    

Both eelgrass and surfgrass may have the epiphytic red seaweed Smithora naiaduum growing on their blades.  Additionally, surfgrass may harbor the red encrusting algae, Melobesia mediocrus.    


This page was created by Mary Jo Adams on 9/12/06.



photo of surfgrass

photo of surfgrass inflorescence

photo of surfgrass fruiting body


photo of surfgrass