Cultivated sunflower

With the knowledge I gained in my botany class today, I returned home and was able to analyse the plants I keep in my room in a new light. I have a sunflower I cut from a plant kept in a small jar on the windowsill. Today in class, the professor explained to us the different types of infloresence in flowers. Infloresence is the structure and form that flowers take when they bloom on a flowering plant. Sunflowers are in the family Asteraceae which includes a very wide variety of flowers. These flowers present in the form of a captiulum which can be most closely compared to a dish. There are flowers along the outside which are usually sterile, and these are what are often presumed to be the only petals. However in the center of the flower, there are very small erect flowers arranged in the 'dish' known as disc flowers. These flowers produce the seeds for the plant, which is why sunflower seeds come from this dish-like area in the center of the flower.