英文摘要 |
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 is 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 five 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 delayed in develop, and elongated later after tetralobed anthers are visible in stamen. The two carpels after subsequent growth and fusion develop into two stigma and two short styles. The four ovules are exposed before the complete fusion of carpels. They are partially separated by incomplete septum afertward. |