Dichocarpum hagiangense from Ha Giang province, northern Vietnam is described and illustrated. Diagnostic features of the new species are a short rhizomatous stem, (2–)3-foliolate or simple leaves, and pink-purple flowers. The described species is distinct from closely allied D. trifoliolatum in having longer sepals, shape and obcordate apex of petal limbs, shorter flower stem, number and tooth shape of basal leaves; it differs from D. basilare and D. carinatum in having stem leaf, retuse apex and longer of central leaflet, number and (2–)3-foliated (or simple) of leaf. With the support of molecular data, the new species was clearly distinguished from other species in the Dichocarpum group by eight autapomorphic characters in nrITS sequence. A key to all species of Dichocarpum is provided. We suggest the IUCN conservation status of D. hagiangense to be “Critically Endangered”. A newest checklist of the family Ranunculaceae in Vietnam is updated.

中文翻译：

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Dichocarpum hagiangense——越南毛茛科新种及更新清单

描述和说明了来自越南北部河江省的 Dichocarpum hagiangense。新种的诊断特征是短的根状茎、(2-)3-小叶或单叶，以及粉紫色的花。所描述的种与近缘 D. trifoliolatum 的区别在于萼片较长，花瓣四肢的形状和倒心形的先端，较短的花茎，基生叶的数量和齿形；它与 D. basilare 和 D. carinatum 的不同之处在于有茎叶、微凹的先端和更长的中央小叶、数量和（2-）3 叶（或单叶）。在分子数据的支持下，通过nrITS序列中的8个自变态特征，该新种与Dichocarpum组中的其他物种有明显的区别。提供了所有 Dichocarpum 物种的钥匙。我们建议 D 的 IUCN 保护状态。hagiangense 被列为“极度濒危”。更新了越南毛茛科的最新清单。