Black tassel • Pterosiphonia bipinnata
{Pterosiphonia = winged tubes}
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Specimen collection number SCL 15314 (right) and PTM 493 (left) in the UBC Herbarium Algae Database. Search the specimen collection number in the database for further information, or search the species for more information. Images courtesy of Sandra Lindstrom.
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Identification
Black tassel is a highly-branched perennial red seaweed. It is dark red to reddish-brown in colour, though when dried out (top layers, when exposed at low tide) it can appear fairly pink. Branches are fine and cylindrical, and at the tips branching occurs in one plane: from either side of an axis as opposed to from all around. This species grows to 12 cm tall or more. An accurate identification of this species requires examination under a microscope or hand lense.
Habitat & Range
Black tassel is a common species in spring; it grows on rock in the low to mid intertidal, however its growth tends to be hampered by herbivores. It is found along semi-exposed to protected shorelines from the Bering Sea and Aleutian Islands in Alaska to southern California. It also occurs in the west Pacific Ocean, along shorelines in Japan and Russia.
Similar Species
Polysiphonia species are also finely- and highly-branched, however in cross-section the axial (central) cells of Polysiphonia are surrounded by fewer pericentral (peripheral) cells than black tassel, which has 11 or 12 pericentral cells. Additionally, branching at the tips of Polysiphonia species occurs at all angles, rather than just in one plane as with black tassel.
Black tassel is a highly-branched perennial red seaweed. It is dark red to reddish-brown in colour, though when dried out (top layers, when exposed at low tide) it can appear fairly pink. Branches are fine and cylindrical, and at the tips branching occurs in one plane: from either side of an axis as opposed to from all around. This species grows to 12 cm tall or more. An accurate identification of this species requires examination under a microscope or hand lense.
Habitat & Range
Black tassel is a common species in spring; it grows on rock in the low to mid intertidal, however its growth tends to be hampered by herbivores. It is found along semi-exposed to protected shorelines from the Bering Sea and Aleutian Islands in Alaska to southern California. It also occurs in the west Pacific Ocean, along shorelines in Japan and Russia.
Similar Species
Polysiphonia species are also finely- and highly-branched, however in cross-section the axial (central) cells of Polysiphonia are surrounded by fewer pericentral (peripheral) cells than black tassel, which has 11 or 12 pericentral cells. Additionally, branching at the tips of Polysiphonia species occurs at all angles, rather than just in one plane as with black tassel.
References
Lindberg, M. and Lindstrom, S. (2010). Pterosiphonia bipinnata Black Tassel. Seaweeds of Alaska. Accessed 21/09/2015.
Druehl, L. 2000. Pacific Seaweeds: A guide to common seaweeds of the west coast. Harbour Publishing: Madeira Park, BC, Canada. P. 108.
O'Clair, R. and Lindsrom, S. Pterosiphonia bipinnata (Postels et Ruprecht) Falkenberg. In Klinkenberg, Brian. (Ed.). E-Flora BC: Electronic Atlas of the Plants of British Columbia. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. Accessed 21/09/2015.
Authors and editors of page
Kelly Fretwell and Brian Starzomski (2015).
Lindberg, M. and Lindstrom, S. (2010). Pterosiphonia bipinnata Black Tassel. Seaweeds of Alaska. Accessed 21/09/2015.
Druehl, L. 2000. Pacific Seaweeds: A guide to common seaweeds of the west coast. Harbour Publishing: Madeira Park, BC, Canada. P. 108.
O'Clair, R. and Lindsrom, S. Pterosiphonia bipinnata (Postels et Ruprecht) Falkenberg. In Klinkenberg, Brian. (Ed.). E-Flora BC: Electronic Atlas of the Plants of British Columbia. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. Accessed 21/09/2015.
Authors and editors of page
Kelly Fretwell and Brian Starzomski (2015).
