Abstract
A species of Calonectria, isolated from a leaf spot of water lily (Nymphaea tetragona) in Guiyang, Guizhou Province, China was shown to be pathogenic by applying Koch's postulates. Identification based on morphological characters and a comparison of sequences from beta-tubulin and translation elongation factor 1 alpha (tef1) genes supported its status as a new species. Calonectria nymphaeae sp. nov. is introduced and compared with similar taxa.