Senjaya Seni Kurnia, Poulsen Axel Dalberg, Ardiyani Marlina, Cronk Quentin C B
Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
Biodiversity Research Centre, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
PhytoKeys. 2025 Aug 22;261:233-273. doi: 10.3897/phytokeys.261.151948. eCollection 2025.
The currently polyphyletic genus Roxb. (Zingiberaceae) has over 260 species widely spread through subtropical and tropical Asia and a complex taxonomic history. This study focuses on the "Carolinensis" clade of hitherto suggested by molecular evidence. We expand on previous research through more comprehensive taxon sampling (about a fivefold increase) and morphological observation. We inferred maximum likelihood (ML) and Bayesian trees based on the nuclear ribosomal internal transcribed spacer (ITS) region, using sequences available on GenBank along with 70 newly generated sequences from this study. Our main findings are as follows: (1) ITS provides a convenient marker for separating members of this clade from other . (2) Phylogenetic reconstruction strongly supports the monophyly of the Carolinensis clade. (3) We identify four subclades with relatively distinct geographical distributions. (4) We determine that morphologically the clade is characterized by inflorescences having densely packed flowers arranged on lateral monochasial cymes, tubular bracteoles, and flowers with oblong or linear labella. (5) The clade is apparently restricted to the east of Huxley's biogeographic line. These findings support the recognition of the Carolinensis clade as a distinct genus. Warb. is the oldest valid name for this lineage, and till the present paper only includes Warb. We present a generic circumscription of the genus comprising 76 species to date placed in . In the present paper, we make 76 new combinations and designate 26 lectotypes. The eastern distribution of the clade offers insights into historical biogeographic barriers and lineage diversification. As such, represents an interesting model for exploring evolutionary and ecological processes in this region, and future phylogenomic studies will be critical for resolving remaining phylogenetic uncertainties and for deepening our understanding of the evolutionary dynamics in this unique lineage.
当前多系的罗克斯伯勒属（姜科）有260多个物种，广泛分布于亚洲亚热带和热带地区，其分类历史复杂。本研究聚焦于迄今分子证据所表明的“卡罗林ensis”分支。我们通过更全面的分类群抽样（约增加五倍）和形态观察，对先前的研究进行了拓展。我们基于核核糖体内部转录间隔区（ITS）区域，利用GenBank上的序列以及本研究新生成的70个序列，推断了最大似然（ML）树和贝叶斯树。我们的主要发现如下：（1）ITS为将该分支的成员与其他成员区分开来提供了一个便利的标记。（2）系统发育重建有力地支持了卡罗林ensis分支的单系性。（3）我们识别出四个地理分布相对不同的亚分支。（4）我们确定该分支在形态上的特征是花序上有密集排列的花，着生于侧生单歧聚伞花序上，有管状小苞片，花有长圆形或线形唇瓣。（5）该分支显然局限于赫胥黎生物地理线以东。这些发现支持将卡罗林ensis分支确认为一个独特的属。瓦尔布是该谱系最古老的有效名称，直到本文为止，仅包括瓦尔布。我们给出了该属的一个分类界定，迄今包括置于其中的76个物种。在本文中，我们进行了76个新组合并指定了26个后选模式。该分支的东部分布为历史生物地理障碍和谱系多样化提供了见解。因此，它代表了探索该地区进化和生态过程的一个有趣模型，未来的系统基因组学研究对于解决剩余的系统发育不确定性以及深化我们对这个独特谱系进化动态的理解至关重要。
