Page 36 - 《广西植物》2020年第1期
P. 36

3 2                                   广  西  植  物                                         40 卷
       Abstract: Chloranthus Swartz is one of the key group for studying the origin and early evolution of angiosperms and some
       of the taxa have been widely cultivated or utilized. Although previous researchers have carried out abundant studies on its
       morphologyꎬ distributionꎬ taxonomyꎬ phylogenyꎬ fossils and chemical constituents. Howeverꎬ our persistent and
       extensive investigations showed that the previous documents of the morphological diversityꎬ habit and geographical distri ̄
       bution in the genus were still largely incompleteꎬ and some problems remained such as discordant classification treat ̄
       mentsꎬ falsely identificationꎬ and following the wrong taxonomic treatment and so on. On the basis of extensively referring
       to the deposited specimens and long ̄term field surveyꎬ in this studyꎬ we describe the morphological diversityꎬ habit and
       geographical distribution of Chloranthus in a more comprehensive and elaborate way. Morphologicallyꎬ the traits of the
       flowers especially the anther connectives are diverse among species but relatively stable within species which are the most
       effective characters in interspecific differentiationꎬ and large variations of the anther connectives were found among the
       populations in C. nervosus which implied that they would be species complex. On habitꎬ C. angustifolius and C. nervosus
       are perennial “evergreen herbs”ꎬ which differ from the two other evergreen subshrub species and the rest perennials the
       aboveground plant organs of which wither annually in autumn and/ or in winter. On geographic distributionꎬ it is verified
       that there display definite horizontal displacements of the distributional ranges (pairwise neighboring but slightly or never
       overlapping in distribution or parapatric distribution ) among the four closely ̄related species with long anther
       connectivesꎻ and C. angustifolius is also distributed in Guizhouꎬ beyond the documented known distribution areas of in
       Hubei and Chongqing. This study not only enriches and improves the understanding of morphological diversityꎬ habitꎬ
       geographical distribution of Chloranthus taxa in Chinaꎬ but also provides more detailed and robust evidence for correct
       identification and classification of different species in Chloranthusꎬ serving as the foundation for future in ̄depth studies
       on speciationꎬ evolution and underlying causes of the special distribution patterns in the genusꎬ and ensuring the safe
       and sustainable development and utilization of these important plant resources.
       Key words: Chloranthus Swartzꎬ morphological diversityꎬ geographic distribution patternꎬ life forms


       金粟兰属( Chloranthus Swartz) 隶属于金粟兰              能基因和植物化学成分等方面开展了广泛研究
   科(Chloranthaceae)ꎬ为多年生草本或常绿亚灌木ꎮ                   (Kongꎬ2000ꎻ孔宏智ꎬ2000aꎬbꎻ孔宏智和陈之端ꎬ
   其须根发达ꎬ无明显主根ꎻ茎分节ꎬ节间膨大ꎻ叶对                           2000ꎻKong et al.ꎬ 2002ꎻ 李 贵 生ꎬ 2005ꎻ 苏 坤 梅ꎬ
   生ꎬ或节间紧缩呈近顶轮生状ꎬ叶缘有锯齿ꎬ托叶                            2007ꎻ曹聪梅等ꎬ2008)ꎮ 金粟兰属植物因具有三
   微小ꎻ花序穗状或分枝排成圆锥状ꎬ顶生或腋生ꎻ                            裂雄蕊这一最为独特的形态特征ꎬ而区别于其他
   花小ꎬ两性ꎬ无花被ꎻ雄蕊一般 3 裂ꎬ着生于子房的                         所有被子植物ꎮ 而这一类型的雄蕊结构化石却在
   远轴面ꎬ药隔合生至顶部、中部或仅基部连合ꎬ卵                            北美东部和欧洲西部的土伦阶( Turonianꎬ ~ 90 百
   形、披针形或线形ꎬ两侧药隔各 1 药室ꎬ中央药隔                          万年) 和坎培阶 - 桑托阶( Campanion ̄Santonianꎬ ~
   一般 2 药室或无ꎻ子房 1 室ꎬ胚珠 1 枚ꎻ核果ꎬ球形、                    84 百万年) 地层中发现ꎬ表明这一类植物起源较
   倒卵形或梨形(吴国芳ꎬ1982ꎻ孔宏智ꎬ2000a)ꎮ 该                     早ꎬ历 史 分 布 比 现 今 分 布 更 为 广 泛 ( Friis et al.ꎬ
   属植物分布于亚洲温带和热带ꎬ多数种类在中国均                            1986ꎻEklund & Kvacekꎬ1998ꎻDoyleꎬ2015)ꎮ 该属
                                                                        ˇ
   有分布ꎬ其中一些种类为中国特有(吴国芳ꎬ1982)ꎮ                        植物现存类群在叶形状、总花梗长度和分叉数目、
       金粟兰属乃至金粟兰科植物具有简化的花部                           雄蕊形状、长短和颜色等形态特征和生活型等方
   结构、化石丰富且年代久远、现存类群( 尤其属) 间                         面在属内具有多样性ꎬ曾被用于属内分类尤其物
   呈洲际间断分布、多数种类生长在阴暗潮湿林下                             种划分 的 依 据 ( 吴 国 芳ꎬ 1980ꎬ 1982ꎻ 王 德 群 等ꎬ
   生境等特点ꎬ被认为是揭示被子植物的起源和早                             1984ꎻ 程 用 谦ꎬ 1985ꎻ 张 遂 申 等ꎬ 1991ꎻ 孔 宏 智ꎬ
   期演化之谜的关键类群之一ꎬ一直以来受到学界                             2000aꎬbꎻ王跃华和杨科ꎬ2000)ꎮ 其中ꎬ一些性状

   的关注(Friis et al.ꎬ1986ꎻEklund et al.ꎬ1997ꎻFeild    如花序轴分叉式样在物种内群体间或群体内个体
   et al.ꎬ2004ꎻZhang et al.ꎬ2011ꎬ2015)ꎮ 前人已对         间也存在显著差异ꎬ甚至一些种类同一植株的花

   该属植物的形态与地理分布、孢粉、染色体、分类、                           序着生位置、数目和花结构在不同发育时期也可
   系统发育、化石、花器官发生、调控性状的关键功                            能存在显著变化ꎮ 早期根据这些性状发表的单穗
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