Euphorbia pulcherrima is a shrub or small tree, typically reaching a height of 0.6–4 metres (2–13 ft). The plant bears dark green dentate leaves that measure 7–16 centimetres (2.8–6.3 in) in length. The colored bracts—which are normally flaming red, with cultivars being orange, pale green, cream, pink, white, or marbled—are often mistaken for flower petals because of their groupings and colors, but are actually leaves.[10][11] The colors of the bracts are created through photoperiodism, meaning that they require darkness (at least fourteen hours at a time for 6–8 weeks in a row) to change color. The plants also require abundant light during the day for the brightest color.[12]The flowers of the poinsettia are unassuming. They are grouped within the cyathia (small yellow structures found in the center of each leaf bunch, or false flowers).[10] Nothing is known about pollination in wild poinsettias, though wasps are noted to occasionally visit the cyathia.[13] All flowers in the Euphorbiaceae are unisexual (either male or female only), and they are often very small in size. In Euphorbia, the flowers are reduced even more and then aggregated into an inflorescence or cluster of flowers.