Investigations following the discovery of an unusual new collection from the Amazon lead to a phylogenetic investigation in order to ascertain its position within the Nyctaginaceae. Two different approaches were used: gene trees from nucleotide sequences of ndhF and ITS aiming to check the phylogenetic position of the new species in the genus Belemia (Nyctaginaceae), using mostly the available data; and a phylogenomic analysis based on full plastome sequences of Caryophyllales and related orders. Following that, a description of the new species, Belemia cordata Harley & Giul., complete with illustrations, comments and conservation status are provided. Distinct from B. fucsioides, the only other species of the genus, the new species has branches and flowers covered in multicellular glandular trichomes, leaves with cordate base, inflorescences in congested cymes and included stamens. The species is classified as Critically Endangered as it has been found in a single location and subsequent expeditions to locate the plant were not successful. The second description of the chloroplast genome of Nyctaginaceae is also provided.

中文翻译：

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Belemia 新种在 nyctaginaceae 中的系统发育定位，以及该属的首次质体描述

在从亚马逊发现一个不寻常的新集合后进行的调查导致了系统发育调查，以确定它在 Nyctaginaceae 中的位置。使用了两种不同的方法： 来自 ndhF 和 ITS 核苷酸序列的基因树旨在检查 Belemia（Nyctaginaceae）属中新物种的系统发育位置，主要使用可用数据；以及基于石竹目和相关目全塑性体序列的系统发育分析。随后，提供了新物种 Belemia cordata Harley & Giul. 的描述，包括插图、评论和保护状态。与该属唯一的其他物种 B. fucsioides 不同，新物种的枝和花被多细胞腺毛状体覆盖，叶子具有心形基部，在拥挤的聚伞花序和包括雄蕊中的花序。该物种被归类为极度濒危物种，因为它是在一个地方发现的，随后对植物进行定位的探险没有成功。还提供了 Nyctaginaceae 叶绿体基因组的第二个描述。