is the yellow form of normally salmon pink T. carnea. It is a self introduced amphidiploid hybrid (chromosomes add) of Australian T. flexuosa and one or other forms of the Aussie T. pauciflora. Two to four 20mm flowers open wide in cooler conditions than the pink form but plants may not show above ground for several years when conditions do not suit. T. imberbis occurs with T. carnea in discrete colonies but it is not common. It stands some 250mm tall in impoverished damp to wet soils and flowers in September to November from the far north to Southland and the Chathams.