A sporophyte development stage that occurs during the interval between the initiation of a sporangium and the onset of senescence. [source: POC:curators]
Comment
A whole plant may continue developmental vegetative growth (GO:0080186) after it has entered the reproductive stage, and it may revert to a stage in which it is no longer producing sporangia, but once it has initiated a single sporangium, it remains in the reproductive stage until senescence or death by some other cause.