Although breeding system investigations were previously performed in only nine of the 100 Tabebuia species, indications of self‐incompatibility have been found in all of them, and the four species studied for the site of incompatibility reaction showed some kind of late‐acting self‐incompatibility. Polyembryony has been found in T. chrysotricha and T. ochracea, with adventitious origin of the extra embryos being shown in the latter. We investigated the breeding system in five species of Tabebuia by hand‐pollination experiments, fluorescence microscopy study of in situ pollen tube growth, and histological analysis of postpollination events. Although both T. chrysotricha and T. heptaphylla developed fruits by self‐pollination, polyembryony was verified only in the former, which indicates that self‐fertility in Tabebuia is not necessarily associated with apomixis. The remaining species were 100% self‐sterile. Although some penetrated ovules in crossed pistils of T. vellosoi were found at the 48‐h interval, n...