Nymphoides aurantiaca (Dalzell) Kuntze, a new record of family Menyanthaceae for the flora of Vietnam

The newly recorded species, Nymphoides aurantiaca (Dalzell) Kuntze belonging to family Menyanthaceae, was discovered at some wetland areas in Lo Go–Xa Mat National Park (Tân Bien, Tây Ninh). This species was found for the first time in 2003 during a research on wetland biodiversity and conservation funded by Tây Ninh Province’s Department of Science and Technology. Special morphological characteristics of the species include floating leaf blades, deeply cordate at base; flowers usually two per node; five dark yellow corollas with fimbriately toothed margins. This aquatic species inhabits standing water bodies such as shallow ponds, flooded lowlands with water depth of 20-40 cm, low turbidity and slightly acidic with pH values ranging from 5.4 to 6.0. The phylogenetic affinity between N. aurantiaca and other Nymphoides species was established based on matK sequence of chloroplast DNA.