江西景天属一新种——溪水景天

A new species of Sedum from Jiangxi:Sedum fluviale

【目的】2021年在中国江西东北部阳际峰国家级自然保护区进行林木种质资源调查时发现一种景天科(Crassulaceae)景天属(Sedum L.)植物,该种与已报道的同属植物均有区别,本文予以论述并确定其分类学地位。【方法】跟踪阳际峰保护区多个种群,在不同物候期进行详细观察和形态学比较,确定其相近种及区别特征,进而通过文献检索和标本查询确定其在全国分布情况。【结果】该种营养枝在幼苗阶段呈莲座状,最为相似种为细小景天(Sedum subtile Miq.),区别特征为新发现种具有发达且3叶轮生的不育枝、花茎上每分枝5~16朵花,苞片匙状倒披针形;细小景天不育枝细弱且叶互生或对生、花茎每分枝3~5朵花、苞片线形。【结论】该种为景天属一新种,命名为“溪水景天”(Sedum fluviale B.Chen&Z.W.Zhu)。该种专一性地生于溪流环境,分布范围较广,包括江西、浙江、福建、安徽、湖南、贵州等省(区、市),此前存在较多错误鉴定的情况。模式标本存放于上海辰山植物标本馆(CSH)。

[Objective]During a survey of forest germplasm resources in the Yangjifeng National Nature Reserve in northeastern Jiangxi,China,in 2021,the authors discovered a plant belonging to the Crassulaceae family and Sedum L.genus.This species differed from previously reported plants of the same genus,and this paper discusses and determines its taxonomic status.[Methods]Multiple populations in Yangjifeng were tracked,and detailed observations and morphological comparisons were conducted at different phenological stages to distinguish commonalities and unique traits.Additionally,its national distribution was determined through literature review and specimen examination.[Results]The species had a lotus-shaped nutritive branch in the seedling stage,which was most similar to Sedum subtile Miq.Distinguishing features included well-developed and trinodal sterile branches,5 to 16 flowers per branch on the flower stem,and spatulate-lanceolate bracts in the former,while the latter had slender sterile branches with alternate or opposite leaves,3 to 5 flowers per branch on the flower stem,and linear bracts.[Conclusion]The study indicated that this was a new species,and was named Sedum fluviale B.Chen&Z.W.Zhu.It was specifically found in stream environments and had a broad distribution,including provinces such as Jiangxi,Zhejiang,Fujian,Anhui,Hunan,and Guizhou.There had been numerous instances of misidentifications in the past.The holotype specimen was stored at the Shanghai Chenshan Herbarium(CSH).