中国藓类植物新记录种——钝叶匍网藓

Moss species newly recorded for China: Mitthyridium obtusifolium

关键词:  海南热带雨林国家公园, 黎母山, 花叶藓科, 新分布, 热带岛屿

Key words:  Hainan Tropical Rainforest National Park, Limushan, Calymperaceae, new distribution, tropical islands

摘要:

海南热带雨林国家公园是中国首批建立的5个国家公园之一,全面的生物多样性调查是园区建设的必要基础。本次研究对黎母山片区的苔藓植物进行了系统的野外调查和标本采集。结果表明:(1)经对标本的形态学观察和文献考证,发现了1个中国新记录种——钝叶匍网藓 [Mitthyridium obtusifolium(Lindb.)H. Rob.]。该种的主要鉴别特征如下:主茎匍匐,枝茎直立; 叶片阔披针形,褶皱较少,先端常圆钝; 叶鞘稍阔,分化边从叶基部延伸至近先端。(2)基于新采集的标本,详细描述了钝叶匍网藓的形态特征并附彩色图版,绘制了该种世界分布图,并编制了中国匍网藓属(Mitthyridium H. Rob.)的分种检索表。(3)文献考证显示,匍网藓属的分类具复杂性和挑战性,该文讨论了钝叶匍网藓与近缘种匍网藓 [Mitthyridium fasciculatum(Hook. & Grev.)H. Rob.]的系统发生关系。匍网藓属主要分布于热带低地,对低地雨林生境的保护和生态恢复具有重要的指示功能,新记录种的发现不仅丰富了海南乃至中国热带苔藓植物的区系资料,也为匍网藓属的分类、鉴定和保护提供了新的科学依据。

Abstract:

Hainan Tropical Rainforest National Park is one of the first five national parks established in China, where comprehensive biodiversity surveys are essential foundations for the construction of the park. The present study investigated the Limushan area for bryophyte diversity through systematic field survey and voucher collection. The results were as follows:(1)Detailed morphological examination of the specimens with consultation with relevant literature revealed one moss species as a new record for China — Mitthyridium obtusifolium(Lindb.)H. Rob. The main distinguishing features of the species include creeping main stems with erect branches; leaves broadly lanceolate, slightly rugose with a rounded-obtuse apex; and leaf sheaths slightly broadened and differentiated borders extending from the leaf base to near the apex.(2)Detailed morphological descriptions and color plates of the species were provided based on the newly collected specimens. A global distribution map of M. obtusifolium was given, showing that this species is primarily found in tropical regions, particularly on islands in the Indian and Pacific Oceans and along adjacent continental coastlines. It typically inhabits tree trunks and decaying wood at elevations below 500 m. The newly recorded occurrence in China represents the northernmost known distribution for this species globally. A classification key was developed to distinguish the three known Mitthyridium species in China: M. fasciculatum(Hook. & Grev.)H. Rob., M. obtusifolium, and M. flavum(Müll. Hal.)H. Rob.(3)A literature review revealed that the taxonomy of Mitthyridium was both complex and challenging. The phylogenetic relationships between Mitthyridium and the related Syrropodon Schwägr. as well as between M. obtusifolium and its related M. fasciculatum, were discussed. Mitthyridium is a mainly tropical lowland distribution genus, thus functioning as an important indicator for conservation and ecological restoration in lowland rainforest habitats. The discovery of new record not only enriches the floristic data of tropical bryophytes in Hainan and even China, but also contributes new scientific insights into the taxonomy, identification, and conservation of the genus Mitthyridium.