What contains the sexual organs of the plant?

The sexual organs of a plant are in the flowers. The pistil (center "post" inside a flower) is the female part of the flower, and the stamens (located around the pistil) are the male parts of the flower. A flower can sometimes pollinate itself, but usually, an intermediary is involved. That is where the term "birds and bees" come from. Bees and small birds try to gather nectar from the plants, and in the process, they knock pollen onto the pistils and carry pollen between plants. Pollen plays the same role in plants that semen plays in humans and other animals.