E-Flora BC: Electronic Atlas of the Flora of British Columbia

Family Description:
Members of this family come in a wide variety of forms, from cylindrical and branched to flattened blades. Some species have a single axial filament, whereas others have a multiaxial filamentous medulla. What unites these species into a single family is the occurrence of the carpogonium at the end of branch of beadlike cells and similarities in the formation of carposporangia after the carpogonium has been fertilized. All of the species described here have an alternation of isomorphic generations, and male and female reproductive structures usually occur on separate individuals.
Species in this family have unusual cell wall carbohydrates that have been shown to have antiviral properties.

Species description:
Northern Red Blade forms a bright, crimson blade that is up to 12 cm (almost 5 in) tall by 4.5 cm (about 1.75 in) wide by late April, after which it grows rapidly. Blades to around a meter (over 3 feet) in diameter have been collected subtidally. The blade is quite thick (not transparent at all), often slightly wrinkled and has a matte finish. It lacks midribs and veins and tapers to a short, slender stipe. The holdfast is very small and discoidal.
Scattered individuals occur most commonly on small rocks in sand or mud. In Southeast Alaska, it grows lower on the rocks than does Red Ribbon (Palmaria mollis). Most specimens of Northern Red Blade are subtidal.

Individuals collected from southern British Columbia/northern Washington were able to withstand a week of immersion in water at a temperature of 25°C (77°F) but died when placed in warmer water.

This species has been used to treat conditions caused by Herpes viruses.