Evolutionary trends in Winteraceae pollen

Abstract

The Winteraceae, being considered as one of the most basal angiosperm families, has been extensively studied palynologically. The present study reviews the characters dispersal unit (monad versus tetrad) and size of the lumina in the tectum in the light of recent molecular research. Monads and small-meshed reticula appear to be derived from large-meshed tetrads. The fossil record supports the apomorphic state of a small-meshed tectum. In contrast to earlier reports, genuine monads are unknown as fossils. The fossil monads recorded so far are considered to be detached from permanent tetrad configurations.