Search

Our understanding of the flora of China has greatly improved during the last 100 years but effective management of the rich biodiversity and unique natural resources requires resolving the taxonomic limitations of existing treatments. Here, we focus on the epiphytic genusScleroglossumwith special emphasis on the occurrences in Hainan and Yunnan of mainland China. By combining fieldwork, herbarium studies, and DNA barcoding we test the hypothesis that this genus is represented by more than one species in China. Our integrative results show the Yunnan accessions are distinct from those in Hainan in both phenotypic and genotypic variation. The Yunnan accessions belong toS. pusillum, whereas the Hainan accessions represent a distinct species displaying the morphological characteristics ofS. sulcatum. Genotypic evidence suggests the occurrence of cryptic diversity among accessions with the morphology ofS. sulcatum. In summary, the study contributes to the crucial assessment of the plant diversity in Yunnan and illustrates the importance of integrating collection efforts and DNA barcoding approaches to enable effective assessment of the epiphytic diversity of Yunnan.

Most of the grammitid ferns, now placed by many authors in a separate family, Grammitidaceae, or a subfamily, Grammitidoideae, of the Polypodiaceae, were at one time classified as members of the genus Polypodium. In 1967 Morton wrote, "Evidence ... has been accumulating in recent years that there are two major groups of species-those centering around the true Polypodium, as typified by P. vulgare L., and those belonging to Grammitis Swartz and some closely related small genera." Ching (1940) created a family, Grammitaceae, to accommodate these dwarf polypodies. In 1947 Holttum recognized the family, which he revised to Grammitidaceae, and later wrote (1955), "There are no intermediates between them and any true Polypodiaceae, and a close relationship seems very doubtful." After treating them, in 1947 and previously, as members of the Polypodiaceae, Copeland came to believe the group should have family status (1951). In her revision of Grammitis in New Guinea, Parris (1983) placed the genus in Grammitidaceae and gave a history of the family classification. Most authors have accorded the grammitid ferns family status, but W. Wagner (1973) retained them in a subfamily, the Grammitidoideae of the Polypodiaceae, and Tryon and Tryon (1982) placed them in a tribe, the Grammitideae of the Poly