In this paper the floral ontogeny and the ovary development of rivina humilis l . were observed . the results showed that ( 1 ) the tepal primordia initiated in 2 / 5 spirals . the abaxial one initiated first , then the adaxial one , finally the lateral two initiated nearly simultaneously . the third one initiated on the position near the first tepal , and there is a gap between itself and the second tepal . ( 2 ) the 4 stamineal primordia initiated in one whorl at the same time . ( 3 ) the carpellary primordium initiated from the abaxial side of flower primordium ; the carpellary primordium grew upwards and towards axis after it was formed , therefore an elliptic orifice was formed at the adaxial position of ovary , which was the remainder of the mouth of ovary before the ovary was fused completely . with the ovary maturing , the orifice was narrowed because of the ovary growth , at last fused completely . the gynoecium is composed of a single carpel . ( 4 ) in the series developmental sections of ovary , the ovular primordium was initiated on the adaxial meristem when the mouth of ovary was formed 对数珠珊瑚的花器官发生和子房的发育过程进行了观察.结果表明: ( 1 )数珠珊瑚花被呈2 / 5螺旋状发生,远轴侧的1枚先发生,其次为近轴侧的1枚发生,最后侧方的2枚花被几乎同时发生,第3枚花被在靠近第1枚的位置发生,第2枚和第3枚之间有1个空隙; ( 2 ) 4枚雄蕊是同时发生的; ( 3 )心皮发生于分生组织的远轴侧,心皮原基形成后,向上向轴生长,在子房成熟前在近轴侧非正中位形成1个孔,该孔为心皮最终愈合前的残迹,到子房成熟时,因子房的生长孔被挤压缩小,在进一步的生长过程中愈合.子房由1枚心皮构成; ( 4 )从子房发育过程的切片看,该植物的胚珠是在子房发生后不久发生的,子房上的圆孔形成时,从近轴侧的分生组织发生胚珠原基,由胚珠原基分化出珠被与珠心
