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, Limu Mountain, Calymperaceae, distribution range extension, tropical islands

摘要:

海南热带雨林国家公园是中国首批建立的五个国家公园之一，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。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是：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。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。文献考证表明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的重要的指示功能，新记录种的发现不仅丰富了海南及中国热带苔藓植物的多样性，也为匍网藓属的分类、鉴定和保护提供了新的科学依据。

Abstract:

The Hainan Tropical Rainforest National Park is among the first five national parks established in China, where comprehensive biodiversity surveys are essential for setting the baseline information for sustainable site development. The present study aimed to investigate 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 has 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 broaden and differentiated border extending from the leaf base to near the apex. Detailed morphological descriptions and color plates of the species are provided based on the newly collected specimens. (2) A global distribution map of M. obtusifolium is 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 meters. The newly recorded occurrence in China represents the northernmost known latitude for this species globally. (3) A dichotomous key is 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. (4) Literature review has revealed that the taxonomy of Mitthyridium is both complex and challenging. The relationships between Mitthyridium and the related Syrropodon Schw?gr. as well as between M. obtusifolium and its related M. fasciculatum, are discussed. The genus Mitthyridium has a mainly tropical lowland distribution, thus functioning as an important indicator for conservation and ecological restoration in lowland rainforest habitats. The new discovery not only enriches the diversity of tropical bryophytes in Hainan and China, but also contributes new scientific insights into the taxonomy, identification, and conservation of the genus Mitthyridium.