Abstract: Huidong is a county of Guangdong Province in southern China, lying in the eastern region of the Guangdong-Hong Kong-Macao Greater Bay, and holds rich biodiversity. However, there is no checklist of lycophytes and ferns available for Huidong due to the lack of a comprehensive survey. Based on field surveys in recent years, the literature, herbarium specimens, and molecular phylogenetic analyses of some groups, we conducted crucial identifications of all specimens available to us from Huidong in order to document the species diversity and identify the floristic characteristics and rare and endangered species of lycophytes and ferns in this county. The main results include these five points: (1) New morphological forms were found in Selaginella heterostachys, Coryphopteris angulariloba, C. chingii, and Diplazium virescens. (2) Sphaerostephanos taiwanensis was confirmed with populations occurring in Guangdong, while Asplenium guangdongense was not supported to be an independent species from A. normale. (3) A population of Vandenboschia lofoushanensis, which had disappeared for nearly a century in the wild, was rediscovered in Huidong. (4) A total of 11 lycophyte species (belonging to 5 genera and 2 families) and 119 fern species (in 62 genera and 23 families) are recognized in Huidong. For ferns in this area, the Asia-Tropic distributing element and the East-Asian element are dominant, each accounting for about 36% species diversity, with relatively rich species in Polypodiaceae (17 spp.), Dryopteridaceae (15 spp.), and Thelypteridaceae (15 spp.). (5) Among lycophytes and ferns in Huidong, thirteen species are rare and/or endangered; eight species hold Class II national protection status in China, with Huperzia javanica and V. lofoushanensis accessed as endangered (EN) under IUCN criteria. A complete list of lycophytes and ferns in Huidong, along with the information on the distribution pattern for each taxon, is provided.

Key words: endangered species, geographical distribution, taxonomy, morphology, local flora

摘要： 惠东县隶属广东省，位于粤港澳大湾区东部，保存有丰富的生物多样性，但惠东的石松类和蕨类植物一直缺乏全面调查。本研究通过野外调查，并结合文献、馆藏标本和部分分子系统学数据，对惠东县石松类和蕨类植物标本进行鉴定，以阐明惠东县石松类和蕨类植物的种类、区系特点、珍稀濒危物种与保护现状。结果表明：(1) 异穗卷柏Selaginella heterostachys、钝角栗金星蕨Coryphopteris angulariloba、秦氏栗金星蕨C. chingii和淡绿短肠蕨Diplazium virescens存在新的形态变异；(2) 确定广东有台湾圆腺蕨Sphaerostephanos taiwanensis的分布，但不支持广东铁角蕨Asplenium guangdongense为独立分类群；(3) 重新发现消失近百年的罗浮山瓶蕨Vandenboschia lofoushanensis的生活居群；(4) 惠东县目前有记录的石松类植物2科5属11种，蕨类植物23科62属119种，本区域的蕨类植物以亚洲热带分布成分和东亚分布成分居多(各占蕨类总种数的约36%)，其中水龙骨科Polypodiaceae (17种)、鳞毛蕨科Dryopteridaceae (15种)和金星蕨科Thelypteridaceae (15种)的种类最为丰富；(5) 区域内珍稀及重点保护的石松类和蕨类植物有13种，其中8种为国家二级保护植物，而长柄石杉Huperzia javanica和罗浮山瓶蕨被评估为濒危(EN)物种。文后附有完整的植物名录。

关键词: 濒危物种, 地理分布, 分类, 形态, 植物区系