Prionitis lanceolata (Harvey)
Description: This plant is erect, up to 30 cm. tall, reddish brown in colour, growing in clusters, and attached to the substrate by small discoid holdfast. The erect portion is narrowly stipitate below, tapering above to a flattened lanceolate portion. The apices of the branches taper gradually to a point. Numerous proliferous flattened short pinnately arranged branchlets occur along the margins of the main axes
Habitat: On rocks in the lower intertidal and upper subtidal zones.
Pacific Coast Distribution: Alaska to Mexico
Adapted from: Robert Scagel, 1972
Research suggestion: Look for galls on this algae: Reference.