Description: The plant is olive brown to yellowish-brown in colour with a conspicuous blade (eroded at maturity), stipe, and holdfast. The holdfast is made up of short, firm root-like structures and is 3-7 cm. long, 5-8 mm. in diameter, merging into a slightly compressed rachis 2-4 cm. long. The rachis in turn merges into the blade, which is linear, tapering gradually to the apex and abruptly to the rachis; the blade is 40-60 cm. long and 3-8 cm. wide with a conspicuous, solid percurrent midrib 4-6 mm. wide.
Habitat: On rocks in the middle and upper intertidal zones in exposed areas.. This species grows at or around zero tide level at Race Rocks. WHen battered by waves and swell it often gets a tattered appearance.
Pacific Coast Distribution: Alaska to California. –Robert Scagel, 1972