Abstract
Aristolochia pseudoutriformis X.X.Zhu & J.S.Ma, sp. nov. and A. yangii X.X.Zhu & J.S.Ma, sp. nov., two new species from Yunnan, China, are described and illustrated here. The former is morphologically similar to A. utriformis and A. forrestiana and the latter is similar to A. cucurbitoides and A. forrestiana. According to Ma's (1989a) classification, both new species belong to Aristolochia subgenus Siphisia on the basis of the 3-lobed gynostemium and oblong anthers that are adnate in pairs, opposite the gynostemium lobes. Meanwhile, the two new species are assessed as Vulnerable (VU D2) according to IUCN Red List criteria.