Which tree is the tallest flowering plant species in the world?

Eucalyptus regnans is the tallest flowering plant species in the world.

This Australian eucalyptus, commonly called the mountain ash or swamp gum, is native to cool, wet forests of Victoria and Tasmania. Exceptional individuals can exceed 100 metres, placing the species among the tallest trees ever measured. The tallest reliably measured living examples are shorter than the historic record trees, many of which were logged.

Unlike conifers such as coast redwoods, Eucalyptus regnans is an angiosperm: it produces flowers and seeds enclosed in fruits. Its small white flowers are followed by woody capsules containing seeds.

The species is adapted to major disturbance. Fire can kill adult trees, but it also opens the capsules and creates conditions for abundant seedling regeneration. “Mountain ash” here refers to the Australian tree and should not be confused with true ash trees in the genus Fraxinus.