This is a species that has gone unnoticed for many years. Even now, all the records are from the Auckland region. For a time it was known as Porpolomopsis lewelliniae but recent sequencing has shown this to be a Humidicutis.

Pileus: 35-50 mm Conical, becoming flat or umbonate, completely pure mauve or lilac. The surface is dry and smooth maybe a little fibrillose, but can have a slightly brownish center. The cap margins split radially through the gills as it matures.
Lamellae: Nearly free or adnexed, lilac to white with lilac tinges. They have a classic brittle, waxy texture typical of the Hygrophoraceae family
Stipe: Up to 70 mm tall and 8 mm thick. It is smooth, dry, hollow, pale lilac, and may feature horizontal, watery-looking bands
Odour/tast: Not recorded.