Marsdenia R.Br. (Apocynaceae: Asclepiadoideae, Marsdeniae) is a species-diverse genus of Apocynaceae from Mexico. Here, a new species, Marsdenia salaschiblii, from the state of Oaxaca in southeastern Mexico, is described and illustrated. The morphological features of this new taxon are different from those of known species of Marsdenia in Mexico. It is morphologically similar to M. propinqua Hemsl. and M. veronicae W.D.Stevens, but can be distinguished by a long pedunculated inflorescence, which is an umbellate thyrsoid with (2) 3 – 4 rachides, and gynostegial corona lobes at the level of the anthers or slightly above them. We provide images to distinguish the new species and to aid in its identification, as well as a key to diagnose the species in Oaxaca. In addition, we suggest the conservation status of the new taxon based on the IUCN criteria and we provide a distribution map for the new Marsdenia.

中文翻译：

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Marsdenia salaschiblii（夹竹桃科：Asclepiadoideae），墨西哥瓦哈卡州东南部的一个新物种

Marsdenia R.Br. （Apocynaceae：Asclepiadoideae，Marsdeniae）是来自墨西哥的Apocynaceae的一个物种多样的属。在这里，描述并举例说明了来自墨西哥东南部瓦哈卡州的一种新种，Marsdenia salaschiblii。这种新的分类单元的形态特征与墨西哥的马斯登尼亚的已知物种不同。在形态上与M. propinqua Hemsl相似。和M. veronicaeWDStevens，但可以通过花序状的长花序来区分，该花序是伞状的甲状腺，具（2）3–4个花序，在花药水平或稍高于花药的位置上有雌性花被冠状花冠裂片。我们提供图像以区分新物种并帮助其识别，以及在瓦哈卡州诊断该物种的关键。此外，我们根据自然保护联盟（IUCN）的标准建议新的分类单元的保护状态，并为新的马斯登尼亚（Marsdenia）提供分布图。