Note on the floral development of Thottea (Aristolochiaceae)

The occurrence of four placentae is a constant character in Thottea. The species can be distinguished by differences in the androecium. The androecial pattern is relatively variable and its rather high plasticity in the genus is suggested to be a derived feature within the family. The gynoecial structure is most remarkable, as the stylar organs do not correspond with the placentae in number nor in position. It is assumed that these organs do not belong to the gynoecium morphologically. They may represent independent, phylogenetically secondary organs, which may function in the capturing of pollen.