Trap: In this plant the stigma becomes receptive first, then the anthers mature afterwards. A means has been evolved by which cross-pollination is encouraged: First – flowers upright, insects push way past downward facing hairs which then prevent their exit. Stigma receptive. Second – flowers pendant, pollen released disting insects which then escape after hairs shed. Stigma withered. Third – insects can make their way to flowers in the upright position with receptive stigmas pollinating as they go down to be trapped again.
Lily: Fig.1 – Red staining cells are the secretory cells present in many stigmas. These form a region receptive to pollen tube growth and extend down to the ovary. Fig.2 – Cross sections down the style. Fig.3 – Cross section of ovary. Three Carpels. Fig. 4&5 – Germinating Pollen. Fig. 6 – Ovule.