Accurate position exchange of stamen and stigma resolves the herkogamy dilemma in a protandrous plant, Ajuga decumbens (Labiatae)

https://de.botany.one/accurate-position-exchange-of-stamen-and-stigma-resolves-the-herkogamy-dilemma-in-a-protandrous-plant-ajuga-decumbens-labiatae/