Festive foliage

We're getting a close look at a poinsettia, a popular plant around Christmas time. Although many people assume the red, white, pink, purple or marbled colours are flowers, they're actually bracts, a type of leaf that helps 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