Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Plant science: Pigment puzzle


J. Am. Chem. Soc. doi:10.1021/ja809065g (2009)

Researchers at Florida International University in Miami have discovered the 'animal' pigment bilirubin in the seeds of the white bird of paradise tree, Strelitzia nicolai. This is the first example of bilirubin occurring naturally in plants.

Cary Pirone and her colleagues cannot yet account for the presence of the bright orange substance, which is a product of the breakdown of the haem chemical group that, in animals, is found in haemoglobin. In plants, haem's normal metabolic product is the light-sensing pigment of the important protein phytochrome.

Although the plant the team studied has white flowers (pictured), the seed part, called the aril, has the hue of oxygenated blood.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Plant science: Pigment puzzle. Nature 458, 10 (2009).

Download citation


Quick links