Abstract: There has long existed a confusion in the nomenclature and locality of the so-called Caesalpinia hypoglauca Chun et How (1958) ("Fenye Sumu"). The author of this paper found that this binonym is a superfluous synonym of Caesalpinia caesia Hand.-Mazz. (1936) (xvGuangxi Yunshi") and its original collections were made in Shiwandashan (located in the south of Guangxi Zhuang Autonomous Region), never in Hainan Island.The name Caesalpinia hypoglauca is based on 3 numbers of specimens collected entirely in Shiwandashan, one of which was G. Fenzel’s collection. The mistake was first made by some taxonomists, such as Chun and How, and later the authors of the Flora Hainanica wrongly took Hainan Island as the locality of Fenzel’s collec? Won.In 1929, G. Fenzel, German silviculturist, made a lot of collections along the Chinese-Vietnamese border as well as in Shiwandashan and Hainan Island. For some reasons the localities of his collections are sometimes confused. Having clarified the nomenclature and locality of the alleged Caesalpinia hypoglauca, the author feels re; sponsible to suggest that Fenzel’s collections should be handled with more care in order to avoid other mistakes.