The micro‐morphological characteristics of <i>Hypodematium</i> Kunze (Hypodematiaceae) from China and their significance in classification

The spore morphology and perispore ornamentation of 14 species of Hypodematium from China have been carefully observed and photographed under light microscope (LM) and scanning electron microscope (SEM) for the first time. The results show that the species can be divided into six groups based on their perispore ornamentation under SEM: 1) H. sinense K.Iwatsuki, H. hirsutum (Don) Ching, H. glanduloso‐pilosum (Tagawa) Ohwi, H. confertivillosum J.X.Li, F.Q.Zhou and X.J.Li, H. chingii J.X.Li and X.J.Li, H. jianxiuii X.J.Li and H. zhangii J.X.Li and X.J.Li with tuberculate ornamentations; 2) H. squamuloso‐pilosum Ching with tuberculiform‐rugulates ornamentations; 3) H. fordii (Bak.) Ching and H. shandongense J.X.Li and X.J.Li with ringed and semi‐ringed ornamentations; 4) H. crenatum (Forssk.) Kuhn and H. gracile Ching with ridged ornamentations; 5) H. mengshanensis J. X.Li and X.J.Li with auricular ornamentations, and 6) H. guilinense J.X.Li and X.J.Li with reticulate ornamentations. These characteristics were stable within species but show significant differences between species. These results not only provide a basis for species identification and classification, but also provide new data for establishing the palynology of ferns, and provide a basis for studying the biodiversity of Hypodematium , which is of great significance for the exploitation and conservation of its resources.