G4-How Plants Sense the Seasons Lower Level-02
One type of plant becomes a flower only once per year. During the time it shows its brilliant red flowers. It is even named after a holiday.. Can you guess its name?

Different from many plants, this plant becomes a flower in the middle of winter. It is called the Christmas Cactus. How does it know Christmas is near? Can it read a calendar? No. It also blooms in areas of the world that do not celebrate Christmas. So how does a plant know what time of the year it is? Can you think of other plants that become flowers in the winter?
Plants can feel the changing of the seasons. You may have seen a pattern most plants follow during the seasons. Most plants will become flowers in the spring and lose their leaves during the fall. How does a plant know what time of year it is? To answer this question, think about how you know the seasons are changing.
Most people living in the US wear different clothes in the summer.
In the winter, we may wear a light jacket or even a heavy coat. These extra layers of clothing help keep us warm.

In the summer, it gets warmer. So we can wear fewer layers or lighter clothing. Summers are warm, so the extreme clothing of winter is no longer needed.
Plants do not sense changes in temperature like we do, but they do see the reason for these changes.