Australia is home to the world’s tallest flowering plant, which are the mountain ash trees found in Victoria and Tasmania. The mountain ash can grow over 110 meters tall and up to 34 meter in girth. Only the giant Redwood trees in California are taller but they are not considered flowering plants since they are conifer trees. Redwood trees also grow much slower than a mountain ash. Redwoods reach their maximum height in 1,200 years while mountain ash can reach their maximum height in as little as 250 years.
Here is a picture of me standing in front of a mountain ash tree in Victoria’s Great Otway Ranges:
As you can see these trees can get very thick if they are old growth but even the younger ones grow to extremely tall heights without being to thick, which is what makes them the world’s tallest flowering tree.