Histological and cytological analysis of microsporogenesis and microgametogenesis of the invasive species Galinsoga quadriradiata Ruiz & Pav. (Asteraceae).
Galinsoga quadriradiata Ruiz & Pav. is an annual weedy plant that can be found all over the world. It belongs to the Asteraceae family and is recognised as one of the invasive foreign plants in Poland, which are native to Central and South America. The aim of this study was to describe the reproductive features of Galinsoga quadriradiata focusing on the changes that occur during microsporogenesis and microgametogenesis along with the morphology of its pollen. As it is typical of the eudicot clade of Angiosperms, cytokinesis of G. quadriradiata is simultaneous. The pollen grains are tricolporate with spiny outer walls and the course of the microsporogenetic process is fairly typical of the Echinatae group of weed plants. The high viability of the pollen grains, which mature unequally in the inflorescences, and the proper course of meiosis determine whether a plant has the invasive character of Galinsoga quadriradiata.