About Calliarthron tuberculosum (Post. & Rupr.) Daws.
Calliarthron tuberculosum (Post. & Rupr.) Daws. is a species of thalloid intertidal red algae. It is the type species of the genus Calliarthron. This alga occurs along the west coast of North America, ranging from the Baja California Peninsula to the Alaska Panhandle. It is most commonly found in low intertidal tidepools located in moderate to exposed coastal habitats. South of Monterey Bay, California, the distribution of Calliarthron tuberculosum overlaps with that of the closely related species C. cheilosporioides. Because the two species look very similar, distinguishing between them requires either molecular sequencing or detailed morphological measurements.
