This is the only tree on Earth that grows intense blue-coloured fruit. It grows in...

For centuries, botanists believed nature had no truly blue fruits. Even those labeled “blue”—like blueberries or blue corn—are, on closer inspection, shades of purple or indigo. But deep in the rainforests of Australia and Southeast Asia grows a tree that defies this rule: Elaeocarpus angustifolius, better known as the blue quandong, blue fig, or blue marble tree.

The fruit of the blue quandong is so vividly cobalt that most assume it’s digitally enhanced. Yet under natural sunlight, it gleams like a metallic jewel. Measuring just 1–2 cm in diameter, these hard, spherical fruits are considered by researchers to have the most intense natural blue hue in the plant kingdom, Forbes reported.

Fruit doesn't contain any blue pigment

What makes this fruit extraordinary is that it contains no blue pigment at all. Unlike most blue plants, which rely on anthocyanins—pigments that shift color with pH—the blue quandong achieves its hue through structural coloration. Scientists discovered this when grinding the fruit to extract pigment: instead of blue, the material turned a dull grey, Forbes reported.