Fig. 4

Coriandrum sativum. Morphogenesis of the umbel (A–E) and ray flowers (F–I). A FUM fractionates umbellet meristems. B The first initiated umbellet begins to fractionate common ray flower/involucel primordia in a spiral sequence. C Umbellets begin to elongate stalks (raylets) which results in their physical separation. When ray flower meristems are fractionating radial flower meristems follow in a centripetal sequence. D Ray flower meristems fractionate floral organs. E Ray flower meristems already develop the gynoecium when radial flowers start to fractionate floral organs. F Naked, spherical ray flower meristem. G First floral organs are initiated from ray flower meristems. H Ray flower meristem before gynoecium initiation. Note enlarged abaxial (sp3) and lateral (sp1) sepal. I Late-stage umbellet with ray flowers showing enlarged petal lobes. For colours and abbreviations, see Fig. 2. Scale bars = 100 µm