Anubias gigantea
... that the aquarium plant Anubias gigantea and the closely related species Anubias afzelii only differ by the shape of their leaf-blades?
... that the <a href="./List_of_freshwater_aquarium_plant_species" id="mwCgA" rel="mw:WikiLink" title="List of freshwater aquarium plant species">aquarium plant</a> <i id="mwCgE"><b id="mwCgI"><a href="./Anubias_gigantea" id="mwCgM" rel="mw:WikiLink" title="Anubias gigantea">Anubias gigantea</a></b></i> and the closely related <a href="./Species" id="mwCgQ" rel="mw:WikiLink" title="Species">species</a> <i id="mwCgU"><a href="./Anubias_afzelii" id="mwCgY" rel="mw:WikiLink" title="Anubias afzelii">Anubias afzelii</a></i> only differ by the shape of their leaf-blades?