The first flower to appear along the path of plant evolution, during the time of the dinosaurs, was a hermaphrodite with petal-like organs arranged in concentric circles, researchers said on Monday.

The bloom had both male and female reproductive organs at the centre, surrounded by multiple layers or “whorls” of petal-like parts called tepals, arranged in sets of three per layer, they wrote in the journal Nature Communications.

The reconstruction, based on the largest dataset of flower traits ever assembled — from 792 existing species — challenges scientific assumptions that the ancestral flower would have had its sex organs and “petals” arranged in a spiral.

Most flowers today have four “whorls” — the outer leaves or sepals, followed by the petals, which enclose the male organs called stamens, with the female organs or carpels at the centre.

Source: AFP