Abstract: A new and distinct cultivar of the red macroalgae Asparagopsis taxiformis named “Icarus,” characterized by significantly smaller internal branching angles, a smaller form when aggregated in tumble culture, and a dark red pigmentation. New branches of this macroalgae are generated prolifically at higher temperatures than wild-type A. taxiformis, making “Icarus” well-suited for commercial growth, e.g., when there is a risk of extreme heat events, in cases of needing to lower the cost of cooling cultivars, or other such conditions.