What are we looking at?

On Poinsettia Day we're taking an up-close look at a poinsettia leaf. Although many people assume the red, white, pink, purple, or marbled colours are flowers, they're actually bracts, a type of leaf that aids in reproduction, usually by turning colour as the plant develops true flowers. On the poinsettia, the bracts, surrounding small yellow clustered buds called cyathia, flag down pollinators just as flower petals do.
© Charles Floyd/Alamy