The circumscriptions of three species of Merostachys, M. medullosa, M. procerrima and M. magnispicula, are modified and a new species, M. soderstromii, is described. Reproductive structures of M. procerrima are described for the first time, and the name is epitypified. All four species are illustrated and notes on distribution, ecology, conservation status are provided.

中文翻译：

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三个 Merostachys 物种（禾本科：竹科：竹科：Arthostylidiinae）的重新界定和来自巴西大西洋森林的一个新物种的描述

修改了M. medulosa、M. procerrima和M. magnispicula三个物种的界限，并描述了一个新物种M. soderstromii。首次描述了M. procerrima 的生殖结构，并对其名称进行了表型化。对所有四个物种都进行了说明，并提供了关于分布、生态、保护状况的说明。