Stylonema alsidiiStylonema alsidii is a species of marine red algae. The type locality is Trieste, Italy, but it has a worldwide distribution.The species was first described by Giovanni Zanardini in 1840 as Bangia alsidii.DistributionIt is one of the algae of the Houtman Abrolhos, found off the coast of Western Australia. It is one of the red seaweeds of South Africa, including the seaweeds of the Cape Peninsula and False Bay.EcologyIt is susceptible to infection by the parasitic oomycete Pythium porphyrae.