Abstract: The flower of the new genus Tetradoxa (Adoxaceae) has been studied in detail. Its flower is almost 4merous. On rare occasions it is 3- merous or 5-merous. Their numerical ratio of calyx- and corolla-- lobes is always equal to one. The variations of the flower parts are not frequency like Adoxa. It is no doubt that the outer lobes are calyxes and the inner lober are corollas. The bundle fusion in the vasculariation of the flower in Tetradoxa is less than that in Adoxa. In our opinion, Tetradoxa is stayed on a original: position in the infrafamiliar evolution.

Key words: Tetradoxa omeiensis (Adoxaceae)

摘要： 对四福花(Tetradoxa omeiennsis)花部进行了详细的解剖观察。其花部整齐，较少特化，维管系统愈合程度较五福花低。其萼与花冠同数，比率始终为1。我们认为四福花应居于科内原始位置。此外，四福花作为一个原始类型，有助于说明五福花萼与花冠”的本质及演化的可能途径。

关键词: 四福花(五福花科), 花部解剖