The anatomical structure changes of cremocarp transection of Changium smyrnioides Wolff, an endemic species of Apiaceae in China, were comparatively observed during fruit development process after falling of flower. The observation results show that, during young fruit phase, middle fruit phase ( including middle fruit stage Ⅰ , Ⅱ and Ⅲ ) and mature fruit phase (including mature fruit stage Ⅰ ,Ⅱ and Ⅲ ) , some characteristics, such as size and shape of fruit transection, thickness and cell morphology and cell layer number of fruit wall (including exocarp, mesocarp and endocarp) , commissure structure, shape and size of endosperm, with or without perisperm, nucellus degenerating or not and vascular bundle morphology, change obviously. During whole development process, shape of mericarp transection changes from sub-pentagonous round to kidney-shaped round. Fruit wall thickness changes from thick to thin, and number of cell layer deceases gradually. Endosperm enlarges gradually and its shape changes from semi-circle to crescent, U-shaped and C-shaped at last. Perisperm disappears and nucellus degenerates gradually. Abscission layer of commissure becomes more and more obviously until to completely separate. Moreover, numbers of vitta and vascular bundle change a little. Vittae can be divided into two kinds of vascular bundle accompanying vitta and fruit wall vitta. There are 4-6 fruit wall vittae in commissure, which is inconsistant with the related description of Changium Wolff.%对中国伞形科(Apiaceae)特有种类明党参(Changium smyrnioides Wolff)花后果实发育过程中果实横切面的解剖结构变化进行了比较观察.结果表明:在幼果发育阶段、中果发育阶段(包含中果期Ⅰ、中果期Ⅱ和中果期Ⅲ)和熟果发育阶段(包含熟果期Ⅰ、熟果期Ⅱ和熟果期Ⅲ),明党参果实横切面的大小和形状、果壁(包括外果壁、中果壁和内果壁)厚度及其细胞形态和层数、合生面结构、胚乳形状及大小、外胚乳存在与否、珠心退化与否以及维管束形态等特征均有明显的变化.在整个发育过程中,明党参分生果横切面的形状由近五边状圆形变化至肾状圆形；果壁由厚变薄且细胞层数逐渐减少；胚乳逐渐增大,从半圆形变化为新月形、马蹄形直至“C”形；外胚乳逐渐消失,珠心逐渐退化；合生面的细胞离层越来越明显直至完全分离.此外,明党参果实中油管和维管束数量变化较小,油管可分为维管束伴生油管和果壁油管；合生面有果壁油管4～6个,此特征与明党参属(Changium Wolff)的相关描述不一致.
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