Ruataniwha Wetlands are a system of man-made wetlands near Twizel. Water levels have for 20 years been artificially managed (high in winter, low in summer) to create kaki habitat but also to create interesting ephemeral wetlands with a varied range of turf plants, including Dysphania pusilla. Riccia cavernosa was found on 24.2.2016 by Aalbert Rebergen, peter de Lange, Peter Heenan and Colin Meurk. Riccia is locally very common along a 50-80cm margin just above the water level.It is found growing on bare dry silt and among sparse turf plant vegetation, incl. Dysphania pusilla, Limosella, Centipeda aotearoana, Glossostigma spp. etc. Identification confirmed by David Glenny. It has been suggested that this is the first NZ record.