本文以光學顯微鏡及掃描式電子顯微鏡觀察臺灣的菟絲子屬(Cuscuta)植物花部構的變異，特別關注於平原菟絲子的不正常花。花部變異包括：(1)花部的缺失；(2)花部不正常的癒合，有些導致花瓣的分離；(3)雄蕊花瓣化；(4)花藥隔的缺失；(5)子房的突出構造；(6)子房上裸露的胚珠。花部的變異在發育早期各花部始原形成時即發生。胚珠位置的不正常、鱗片可能與花絲或花瓣側面癒合成一體，這些變異現象為首次發現於菟絲子屬植物。

The variations in floral structure of Cuscuta in Taiwan were studied with special reference to C. compestris. The variations of t he floral structure were described and illustrated by using light and scanning electron microscopyl. The variations including the flowing: (1) the absence of floral organs; (2) the abnormal fusion of floral organs; (3) petaloid stamens; (4) the lack of distinctive anther lobes; (5) the unusual protrusions on ovaries; and (6) the extrusion of ovule on ovary surfaces. The variations occur in early devlepmental staes when the primordial of floral organ were initiated. The findings that the abnormal position of the ovule and the lateral fusion of the scale with the filament or the petal in the species of Cuscuta are first time reported here.