Hypnobartlettia fontana is an environmental form of Cratoneuropsis relaxa (Bryophyta: Amblystegiaceae)

Abstract The aquatic moss Hypnobartlettia fontana Ochyra was described, and placed in its own family, the Hypnobartlettiaceae, based on material collected at Te Waikoropupuu (“Pupu Springs”), Takaka, Nelson, New Zealand. It is known only from the type locality. Based on morphological evidence, we conclude Hypnobartlettia fontana is an environmentally induced form of the very variable Cratoneuropsis relaxa (Hook.f. & Wilson) Broth, modified in its morphology by the unusual physical features of its habitat in Pupu Springs. Data from published molecular studies relevant to this conclusion, and which do not support it, are equivocal and confounded by incorrectly identified material.