Where do poinsettias grow?

The flower is where the poinsettia bloom is located.

Specifically, the flower blooms a dainty, inconspicuous yellow. But it is surrounded by modified leaves called bracts. The true bracts that immediately surround the flower are always red in color. The transitional bracts that are found between the true bracts and the plant's regular leaves start out green in color. But they change to a bright red color by the time that the plant blooms in December.

Poinsettia admirers often mistakenly describe the color change in the transitional bracts as a "bloom."