- Blue markers: specimen records
- Yellow marker: type locality, if present
- Red markers: endpoints of range from literature
Illustration from DeCew's Guide to the Seaweeds of British Columbia, Washington, Oregon, and Northern California
Illustration from DeCew's Guide to the Seaweeds of British Columbia, Washington, Oregon, and Northern California
Ptilota C. Agardh 1817
Thalli large, feathery, several cells thick throughout; each primary axis bearing 2 primary laterals from alternate cells; 1 lateral frequently developing ahead of other, but each of indeterminate growth. All branches more or less compressed; ultimate branchlets resembling minute leaflets, often with serrate margins, each serration a potential fertile filament. Entire thallus corticated except at apices. Cells uninucleate. Tetrasporangia tetrahedrally divided, borne on margins of ultimate branchlets. Spermatangia rare; when present, in irregular clusters on determinate branchlets or arising from serrations of branchlets. Procarps borne in axils of ultimate branchlets, each procarp with 1 4-celled carpogonial branch and 2 or 3 groups of sterile cells, the terminal group bearing a colorless hair. Carpogonium after fertilization fusing with auxiliary cell through a connecting cell. Gonimoblast with fairly massive, filamentous involucre arising from lower vegetative portion of branch; nearly all cells becoming carposporangia.
Ptilota filicina J. Ag.
J. Agardh 1876: 76; Abbott 1972b: 264. Ptilota plumosa var. filicina Farlow 1875: 374 (in part). P. filicina (Farl.) J. Ag. 1885: 6 (in part). P. tenuis Kylin 1925: 60.
Thalli 10-35(60) cm tall, dark red, frequently drying to black, with 1 major axis or with several branches strongly developed; each order of branches with opposite pairs of branchlets, the branchlets alike in tetrasporangial thalli, unlike in spermatangial and cystocarpic thalli, ultimate branchlets leaflike, the margins sharply serrate on each side, the apices acute; tetrasporangia forming first on adaxial side, then involving entire leaflet, terminal on filaments, surrounded by sterile filaments; spermatangial clusters many, terminal on filaments arising from serrations of determinate branchlets; cystocarps surmounting apex of determinate branchlets, heavily covered by involucral filaments arising from lower portions of branchlet.
Locally abundant, saxicolous, low intertidal, Alaska to Punta Baja, Baja Calif. Also known from Japan. Type locality: San Francisco, Calif.
Excerpt from Abbott, I. A., & Hollenberg, G. J. (1976). Marine algae of California. Stanford University Press, Stanford, California. xii [xiii] + 827 pp., 701 figs.
