Devil Weed
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Scientific Name
Sargassum horneri - Visit algaeBASE for full scientific classification.
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DescriptionSargassum horneri. © 2009 Jessie Altstatt.
- Annual brown algae, up to about 15 feet long.
- Small, fern-like leaf blades on wiry "stems" with many small air bladders.
- Forms very dense groves.
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Habitat
- Occurs in the intertidal zone and down to depths of 100 feet.
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Invasion Pathways and Distribution
- Native to warm seas in Japan and Korea.
- Extensive natural dispersal capabilities via drifting fragments.
- Can spread by attaching to vessel hulls or by drifting.
- Invasive in Baja California, Mexico, southern California, and the California Channel Islands.
- First reported in California in 2003.
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Life History
- Capable of self-fertilization.
- Young plants grow from embryos released from numerous, conspicuous, chili pepper-shaped reproductive structures.
- Completes its life cycle in approximately one year.
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Impacts
- Spreads quickly.
- Areas in southern California currently dominated by this species that thrives in warm water conditions.
- Competes with natives for space and light.
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References and Useful Links
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