Hydrostachys flabellifera, a new species of Hydrostachyaceae found in a stream in Manandriana, Madagascar, is described and illustrated herein. It is similar to H. verruculosa and H. laciniata in morphology, but can be distinguished from them by its leaves with sparsely arranged, flabelliform and palmately parted emergences, obvious rachis and the pattern of segments arranged on the male bracts. Molecular phylogenetic analysis of the nuclear ribosomal internal transcribed spacer (ITS) dataset provides a robust support for it as a new species as well.

中文翻译：

---

Hydrostachys flabellifera（Hydrostachyaceae），来自马达加斯加的新物种

本文描述并举例说明了水生水柏，一种在马达加斯加的Manandriana的溪流中发现的水生水苏科的新物种。它在形态上与普通疣猴和瓢虫相似，但可以通过其叶片稀疏排列，扇形和掌状分开的出芽，明显的轴和在雄性act片上排列的节段的模式与它们区别。核糖体内部转录间隔子（ITS）数据集的分子系统发育分析也为它作为新物种提供了有力的支持。