 More complex reproductive strategies include secondary pollen presentation, heterodistyly, and unisexual flowers.Secondary pollen presentation (also known as stylar pollen presentation or ixoroid pollen mechanism) is especially known from the Gardenieae and related tribes.The flowers are proterandrous and the pollen is shed early onto the outside of the stigmas or the upper part of the style, which serve as a 'receptaculum pollinis'.