Abstract Taxonomic difficulties have persisted within the genus Ruppia for a long time. We first unravel misconceptions as perceived on different continents and subsequently present a revised interpretation of the identity and typification of three European taxa at species level: Ruppia maritima L., Ruppia spiralis L. ex Dumortier, and Ruppia cirrhosa (Petagna) Grande. To do this, historical specimens, illustrations and original descriptions were studied. We supersede a previous choice of the figure of Buccaferrea maritima, foliis minus acutis Micheli (1729) as the lectotype of R. maritima and type species of the genus Ruppia owing to a serious conflict with the protologue. Based on a meticulous interpretation of protologues and figures in a historical context, we reject the recent view of assigning R. cirrhosa and its proposed lectotype (iconotype) as a homotypic synonym of R. maritima. We agree with an earlier lectotypification of R. spiralis, though for another reason than the above-mentioned abused homotypy. Consequently, R. cirrhosa is a synonym of neither R. maritima or R. spiralis, based on material from Petagna in the Herbarium of Naples designated as the holotype of R. cirrhosa. We argue for three species to be considered as fully independent taxa: R. maritima, R. spiralis and R. cirrhosa.

中文翻译：

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关于三个混淆分类群的典型化和地位的深刻观点和论述：Ruppi maritima、R.spirilis 和 R. cirrhosa

摘要 Ruppia 属长期以来一直存在分类学困难。我们首先解开在不同大陆上的误解，然后在物种水平上对三个欧洲分类群的身份和典型进行了修订解释：Ruppia maritima L.、Ruppia spinis L. ex Dumortier 和 Ruppia cirrhosa (Petagna) Grande。为此，研究了历史标本、插图和原始描述。由于与原始物种的严重冲突，我们取代了先前选择的 Buccaferrea maritima, foliis minus acutis Micheli (1729) 作为 R. maritima 和 Ruppia 属的模式种的选型。基于对历史背景下的原型和人物的细致解释，我们拒绝最近将 R 分配给 R 的观点。cirrhosa 及其提议的 lectotype (iconotype) 作为 R. maritima 的同型同义词。我们同意早先对 R. spinotypification 的 lectotypification，尽管除了上述滥用的同型之外还有另一个原因。因此，根据来自那不勒斯植物标本馆中被指定为 R. cirrhosa 正模的 Petagna 材料，R. cirrhosa 既不是 R. maritima 也不是 R. spinis 的同义词。我们主张将三个物种视为完全独立的分类群：R. maritima、R. spinis 和 R. cirrhosa。