not-yet-known not-yet-known not-yet-known unknown The hair types of stipe, rachis, costae, fronds and indusia of 15 species of Hypodematium from China have been carefully observed and photographed under anatomical microscope and scanning electron microscope (SEM) for the first time. The results show that the species can be divided into tree groups based on their rod-shaped glandular hairs and non-glandular hairs under SEM: 1) H. sinense K. Iwatsuki and H. fordii (Bak.) Ching with rod-shaped glandular hairs; 2) H. crenatum (Forssk.) Kuhn, H. hirsutum (Don) Ching, H. guilinense J. X. Li & X. J. Li and H. zhangii J. X. Li & X. J. Li with non-glandular hairs; 3) H. confertivillosum J. X. Li, F. Q. Zhou & X. J. Li, H. squamuloso-pilosum Ching, H. mengshanensis J. X. Li & X. J. Li, H. shandongense J. X. Li & X. J. Li, H. gracile Ching, H. glanduloso-pilosum (Tagawa) Ohwi, H. jianxiuii X. J. Li, H. chingii J. X. Li & X. J. Li and H. taishanensis J. X. Li. & X. J. Li with rod-shaped glandular hairs and non-glandular hairs. These characteristics were stable within species but show significant differences between species, which is combined with palynology, these results not only provide new data of submicroscopic structure characteristics for the species identification and systematic classification for the first time, but also provide a basis for studying the biodiversity of Hypodematium, which is of great significance for the exploitation and conservation of its resources.

The spore morphology and perispore ornamentation of 14 plants of Hypodematium of China were carefully observed and photographed under light microscope (LM) and scanning electron microscope (SEM) in this paper for the first time. The results showed that the perispore ornamentation of all species of the Hypodematium that were divided into six types by SEM were as follow: H. sinense, H. hirsutum, H. glanduloso-pilosum, H. confertivillosum, H. chingii, H. jianxiuii and H. zhangii with tuberculate ornamentations; H. squamuloso-pilosum with tuberculiform-rugulates ornamentations; H. fordii and H. shandongense with ringed and semi-ringed ornamentations; H. crenatum and H. gracile with ridged ornamentations; H. mengshanensis with auricular ornamentations; H. guilinense with reticulate ornamentations. These characteristics were stable in the intra-species with significant differences between interspecies. It not only provides an palynological important scientific basis for species identification and interspecific classification, but also provides a new data for the establishment of palynology of ferns, and provides a scientific basis for the biodiversity of Hypodematium, which is of great significance for the exploitation and conservation of its resources.