旋花亚科植物成熟花器官十分相似，为探究其中系统演化关系，从比较形态学和花器官发生发育的角度研究旋花科中的代表植物。以旋花亚科中旋花族的田旋花、打碗花，番薯族的圆叶牵牛、茑萝等为研究对象，从形态学的角度研究其种子、幼苗、叶型以及成熟花器官，并用扫描电镜对各个花发育阶段的过程进行了观察研究。结果显示：（1）种子及幼苗的形态在番薯族的分类中价值不大；（2）叶型可以有效地区分开所研究的几个种，在旋花亚科属间和属内分类中都有很大的价值；（3）苞片的大小形状及着生位置、花萼的形态特征、雄蕊是否等长、柱头数目和形状、子房的室数以及胚珠数目是旋花科植物属间分类的重要依据。（4）研究所选取的四种植物虽然在比较形态上有诸多不同，但在花器官发育初期及整个过程中是非常相似的，直到花发育的中晚期才显现出不同，生长成不同的形态；（5）花器官的发生是向心式的，即按照花萼原基、花冠原基、雄蕊原基和雌蕊原基的顺序发生，但雄蕊却发育得比花冠原基快；（6）花萼原基以2/5螺旋的方式发生的，这就导致在发育早期，五枚花萼的大小有很大的差异，直到发育中后期才逐渐减小差异。而其它花器官，如花冠，雄蕊的原基都是五枚同时发生的；（7）五枚花冠原基各自发生，到发育中晚期才从基部愈合。

The flowers of plants in Convolvuloideae are similar.To explore the phylogenetic relationship among these species,we researched them in comparative morphological study and floral ontogeny. Experiments were designed to observe and record the morphology of the seed, seedlings, leaves, flowers and floral ontogeny of some typical plants(Ipomoea purpurea (L.) Roth and Ipomoea quamoclit L. in Ipomoeeae, Convolvulus arvensis Linn. and Calystegia hederacea Wall. ex Roxb. in Convolvuleae), and the main experiments are dissecting the flower primordia under the stereoscope and taking photographs of the different periods using scanning electron microscope.The results turn out :(1)The morphology of the seed and seedlings does’t has much value in taxonomy of Ipomoeeae.(2)The morphology of leaves can differentiate these species effectively.(3)The size, shape and location of the bracts, the feature of calyx, whether the stamens are the same long, the account and shape of column head, the account of locules and ovules are important supports in taxonomy of Convolvuloideae.(4)Though the four major species have many differences in their mature plants, they are very similar in floral ontogeny and the early floral development period until the later period.(5)The floral ontogeny in these four species is Centripetal development, which means the order of calyx primordias, petal primordias, stamen primordias and pistil primordias. But the stamens primordias grow faster than petal primordias.(6)The calyx occurs in 2/5 spiral development mode, which makes the calyxs in the different size until the later development period. The five primordias of petal and stamen occur at the same time.(7)The five petal primordias occur solely, then they fuse later period.