Osmundea spectabilis (Postels et Ruprecht) K.W. Nam
Sea Laurel
Rhodomelaceae

Introduction to the Algae

Photograph

© Michael Hawkes     (Photo ID #17078)


Map

E-Flora BC Static Map

Distribution of Osmundea spectabilis
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Species Information

Family Description:
Four or more cells of the same height as the axial cell are cut off the various faces of the axial cell; these are called pericentral cells. Tetrasporangia are tetrahedrally divided. Each cystocarp is surrounded by a well-developed pericarp.
Species description:
Sea Laurel is a purplish red alga that grows up to 30 cm (12 in) tall, but is usually much shorter, 5 to 15 cm or 2 to 6 in high. The erect and flattened blades grow in dense clumps, and each bears two or three orders of branching on its upper two-thirds (the lower parts are bare because the branches that occurred there when the individual was younger have fallen off). On each blade, the blunt-tipped branches are short at the top and become progressively longer below. Midribs are lacking, and each ultimate branchlet has a shallow notch at its tip. The blades have a rather tough texture because they are corticated throughout. The basal holdfast is small and discoidal.

Another distinctive feature of Sea Laurel is that it gives off a pungent odor, especially when it is damaged. This odor is due to the presence of compounds that contain halogens such as iodine, bromine and chlorine. Some scientists have speculated that these secondary metabolites might function to repel epiphytes and/or herbivores.

At maturity, the tips of the branches of Sea Laurel swell and male or female reproductive structures develop here. Tetrasporangia are scattered in the cortex of short, dichotomously branched branchlets.

This species grows on rocks.

SourceNorth Pacific Seaweeds

Habitat and Range

Bathymetry: low intertidal and subtidal to 11 meters (35 feet)

World Distribution: northern Southeast Alaska to Baja California, Mexico

SourceNorth Pacific Seaweeds

Synonyms

Synonyms and Alternate Names:
Laurencia spectabilis