Undaria pinnatifida
(Harvey) SuringarKey Characteristics
- Holdfast with haptera; short, flat stipe and single blade
- Blade thin in texture, especially when young, with central midrib, deep, sometimes finger-like lobes along the margins, and tufts of tiny hairs on the surface.
- Conspicuous sporophyll borne on stipe of mature plants; frilled and folded, tough
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Database links
- Blue markers: specimen records
- Yellow marker: type locality, if present
- Red markers: endpoints of range from literature
View map from the Consortium of Pacific Northwest Herbaria
Notes: In California, Undaria is found in: Mission Bay, San Diego; Santa Catalina Island; Los Angeles-Long Beach harbors; Channel Islands Harbor, Port Hueneme; Santa Barbara Harbor; Monterey Harbor; Half Moon Bay; and San Francisco Bay.
Status: Native range is Korea, Japan and northern China; first reported in Los Angeles Harbor, California in 2000. Also non-native in Atlantic and Mediterranean Europe, Australia, New Zealand, and Argentina.
Habitat: Chiefly in harbors, except at Santa Catalina Island, where it has joined a kelp forest community.
Life History: Alternation of heteromorphic phases (large diploid sporophyte and microscopic haploid dioecious gametophytes). Juveniles are very delicate, oval blades without lobes, but tufts of hairs are visible. Growth rate very fast.
Not in Marine Algae of California (1976).
Excerpt from Abbott, I. A., & Hollenberg, G. J. (1976). Marine algae of California. Stanford University Press, Stanford, California. xii [xiii] + 827 pp., 701 figs.
NON-NATIVE
Vertical Distribution: Subtidal
Frequency: Uncommon
Substrate: Rock, wood, cobble
Type locality: Shimoda, Japan.
