Ptilota filicina

Thallus bushy, caespitose, gregarious, (5)-20-40(-60) cm high, violet-carmine or dark-red. Branching in one plane (to five orders), first irregular alternate or lateral and then pinnate. Main axes and branches compressed, flattened and flat (1)-1.5-2(-3) mm wide, tapering to apices. Branches covered by indeterminate and determinate branchlets that differ in size and shape. Determinate branchlets, 3-5 mm length, flat, lanceolate, leaf-like, serrulate at margins and with acute tips. Indeterminate branchlets shortened or pinnately branched. Sporangia and cystocarps develop on the top of the both indeterminate and determinate branchlets. Attachment by discoid holdfast. Growing on rocky (in sites exposed to strong wave), muddy and muddy-sandy bottom with stones, at low intertidal to subtidal.

Pacific boreal species. North America. Japan, Korea, Russia (Commander Islands, Kamchatka, Sakhalin Island, the Peter Great Bay).