Archaefructus
An alternate interpretation of the same fossil has the long stem as an inflorescence rather than a flower, with staminate (male) flowers below and pistillate (female) flower above.  The discovery of Archaefructus eoflora supports this interpretation, because a bisexual flower is present between staminate and pistillate organs. If this is correct, Archaefructus may not be basal within angiosperms, but it may be close to the Nymphaeales or the basal eudicots.