What is the world’s tallest flowering plant species, with eucalyptus trees exceeding 100 metres?

Eucalyptus regnans is the world’s tallest flowering plant species, with some trees exceeding 100 metres. It is also called mountain ash or swamp gum and grows naturally in southeastern Australia, especially Victoria and Tasmania.

The species is a eucalypt and therefore an angiosperm, meaning it produces flowers and seeds enclosed within fruits. Its small, pale flowers attract insects and other animals, while its leaves contain aromatic oils typical of many eucalyptus species.

Several historic mountain ash trees were measured above 100 metres. Modern forests contain fewer extreme giants because logging, wildfire, land clearing, and tree age have reduced old-growth stands. The species can regenerate after fire, but repeated severe fires may prevent mature forests from returning.

Eucalyptus regnans is sometimes confused with the coast redwood, Sequoia sempervirens. Coast redwoods can also exceed 100 metres and are taller in some individual records, but they are conifers, not flowering plants. Eucalyptus regnans holds the flowering-plant distinction.