Thallus is an undivided, cordate to lanceolate blade, to 40 cm, very rubbery, and usually an iridescent brownish or purplish red in colour. This alga has a perennial, fleshy holdfast out of which a 3-6 cm stipe grows. Northern specimens are smaller than those found from British Columbia south.
This annual (with perennial crustose base) grows on rock in the low intertidal of semi-protected to exposed habitats.
Mazzaella splendens is a red algae with separate male and female thalli and three different life history phases.
Most similar to Mazzaella flaccida (can be virtually indistinguishable in the field).
Gigartina cordata var. splendens (Setchell & N.L.Gardner) D.H.Kim, 1976 (synonym)
Iridaea cordata var. splendens (Setchell & N.L.Gardner) I.A.Abbott, 1972
Iridaea coriacea (Setchell & Gardner) Scagel, 1957 (synonym)
Iridaea reediae (Setchell & N.L.Gardner) Papenfuss, 1958
Iridaea sinicola (Setchell & N.L.Gardner) Papenfuss, 1958
Iridaea splendens (Setchell & N.L.Gardner) Papenfuss, 1958
Iridophycus coriaceus Setchell & N.L.Gardner, 1937
Iridophycus reediae Setchell & N.L.Gardner, 1937
Iridophycus sinicola Setchell & N.L.Gardner, 1937
Iridophycus splendens Setchell & N.L.Gardner, 1937
Direct children (1):
Subspecies Mazzaella splendens subsp. fulgens (Setchell & N.L.Gardner) Hughey & Hommersand, 2010