Cyphostemma calcarium Rabarij & L.M.Lu, sp. nov., is herein described as a new species found on limestone outcrops in northern Madagascar. Its diagnostic morphological characteristics were compared to the species occurring in the Ankarana Special Reserve. We present detailed descriptions, illustrations, distribution map, and a preliminary conservation assessment of the species. An identification key to all known species of Cyphostemma from the Ankarana Special Reserve is also provided.

中文翻译：

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Cyphostemma calcarium，来自马达加斯加安卡拉纳特别保护区的葡萄科新种

Cyphostemma calcarium Rabarij & LMLu, sp. nov.，在本文中被描述为在马达加斯加北部的石灰岩露头上发现的新物种。将其诊断形态特征与出现在安卡拉纳特别保护区的物种进行了比较。我们提供了该物种的详细描述、插图、分布图和初步保护评估。还提供了来自安卡拉纳特别保护区的所有已知 Cyphostemma 物种的识别密钥。