Porpolomopsis lewelliniae, commonly known as the mauve splitting wax-cap, is a gilled fungus of the waxcap family found in wet forests of eastern Australia and New Zealand. The small mauve- or lilac-coloured mushrooms are fairly common and appear in moss or leaf litter on the forest floor in autumn, and are biotrophic. The key distinguishing feature is the splitting of the cap dividing down the middle of the individual gills.