Hedophyllum sessile (C.Agardh) Setchell
Annotated by Robert F. Scagel.

Washington: San Juan: South of Deadman Bay, San Juan Island.
48.616667° N, 123.15° W,
On rocks in the lower intertidal zone.; rock. 16
Thallus at maturity an ample, usually much divided blade attached to the substratum by numerous branched haptera which arise along the sessile margin of the blade. The distal portion of the blade is usually densely bullate. Colour olive brown to brownish black. Https://oregonflora.org/collections/individual/index.php?occid=4673930.

Robert F. Scagel 23, 1955-7-10
OSC, Catalog: OSC-A-003213, Accession Number: 9990