Abstract

Abstract: The initiation and developmental features of floral organs of Cuscuta australis R. Br. Were examined with the scanning electron and light microscopy. The sequence of initiation of the floral organs in a flower bud is that of sepals, stamens, petals and gynoecium. The first sepal are initiated laterally; the remaining four sepals are initiated in helical succession. The five petals are initiated alternating with the sepals. The five stamens are initiated slightly early, and alternating with the petals. The scales arise at the base of stamen, when two stigma are visible. Two opposite carpels arise with four ovules and fuse toward apex gradually, after all other floral organs are initiated. The five sepals mature first, curve at the tips and enclose the other organs. The five Petals are after subsequent growth and fusion develop into two short styles. The four ovules are exposed before the complete fusion of carpels. They are separated by incomplete septum afterward.

中文摘要

以掃瞄電子和光學顯微鏡檢探究旋花科植物菟絲子(Cuscuta australis)花部的發育情形。花之各部始原依萼片、雄蕊、花瓣及心皮之順序出現。除記述發育時花部的特徵外並和旋花科及其他植物比較。兩個心皮先端尚未癒合之前，胚珠很早就出現在雌蕊上，此點較為特殊。又起源為基生的胚珠因具不完全隔板而看似中軸胎座。