Yes, from a botanical perspective, there are indeed many different colors of poinsettias besides the classic, ubiquitous red. The species *Euphorbia pulcherrima*, which we cultivate as poinsettia, possesses a remarkable genetic and physiological capacity for variation in the color of its showy structures, which are often mistaken for flowers.
The vibrant colored parts of a poinsettia are not petals; they are specialized leaves called bracts. The actual flowers are the small, yellow, and relatively inconspicuous berry-like structures, known as cyathia, clustered at the center of the bracts. The plant's energy is directed into changing the color of these bracts to attract pollinators to its tiny true flowers. This distinction is crucial because the color variations we see are primarily expressions of pigmentation within these foliar structures, not the floral organs themselves.
The color display in poinsettia bracts is governed by two main types of pigments working in concert or in isolation:
Anthocyanins: These are water-soluble pigments that appear red, purple, or blue depending on the pH. In traditional red poinsettias, specific anthocyanins are produced in high concentrations, masking other pigments and creating the intense red hue.
Carotenoids: These are fat-soluble pigments that produce yellow, orange, and deep red colors. They are always present in the leaves and bracts but are often overshadowed by anthocyanins. In varieties where anthocyanin production is suppressed or absent, these carotenoid pigments become the dominant visual color.
The final bract color is a complex interaction between the genetics that control the production of these pigments and the environmental conditions the plant experiences during the critical color-development phase.
Through extensive selective breeding and hybridization, horticulturists have developed numerous cultivars that emphasize different pigment expressions, resulting in a wide commercial palette. These cultivated varieties showcase the plant's inherent plasticity.
Pink and Marbled Varieties: These cultivars are bred to produce lower levels or different types of anthocyanins. The resulting color is a softer pink or a blend (marble) of pink and white, where the underlying cream or yellow tones from carotenoids and the lack of dense red pigment become visible.
White and Cream Varieties: In these plants, the genetic pathway for anthocyanin production is effectively switched off. Without the red pigment, the bracts display their base color, which is a creamy white or ivory, sometimes with subtle green veining. The carotenoid pigments may contribute a slight yellow tint.
Orange and Peach Varieties: This color spectrum is achieved through breeding that promotes the expression of specific carotenoid pigments while also allowing for a controlled presence of anthocyanins. The combination can create vibrant oranges, salmons, and delicate peach tones.
Novelty and Dyed Varieties: It is also common to find poinsettias in shades like blue, purple, or with glittered edges. It is important to note botanically that these are not natural pigment expressions. They are created by applying floral dyes or paints to the surface of white-bracted cultivars after they have grown, a process that does not alter the plant's intrinsic genetics.
