A new species from the Mascarene Islands of Mauritius, Reunion, Rodrigues and associated small islands, Madagascar, as well as from the coastal region of KwaZulu-Natal, South Africa and Mozambique, is described. This species is confined to coastal dunes and sandstone rock and is characterized by its prostrate habit, densely clustered leaves, virtually thornless young branches, spreading over the sand dunes or hanging curtain-like over sandstone cliffs above the sea. The new species resembles L. acutifolium E. Mey, that is found in the interior of KwaZulu-Natal, but differs in habitat, growth form, leaf shape. size and succulency.