New morphological and DNA evidence supports the existence of Z. M. Mao (Calligoneae, Polygonaceae) in China.

Z. M. Mao, a species regarded as endemic to China, was thought to be nonexistent owing to a lack of scientific records. The similarity of to Turcz. warranted an investigation into the taxonomical relationship between these species. In this study, a naturally occurring population of was discovered and the taxonomical relationships of this species with were resolved. Morphological traits, including fruit and flower characteristics, as well as nuclear (ETS, ITS) and chloroplast (, , , L, and ) DNA sequence data were studied to confirm the taxonomic status of . The nrDNA data (ITS1-2 and ETS) from reflected variability from the whole complex, showing distinctive haplotypes in the Calligonum sect. Medusa Sosk. & Alexandr. The cpDNA data supplied similar evidence, showing unique branching in Bayesian and ML tree analyses. The specific status of is confirmed based on both morphological and molecular analyses. Here we present a revised description of along with its DNA barcode and discuss suggestions for the conservation of this species. Based on current evidence, this species was evaluated as Critically Endangered (CR) according to the IUCN criteria.