Plant of the week – Eucalyptus regnans

The mighty Mountain Ash.  A stunning giant of our hillside forests.

Plant of the Week – Eucalyptus regnans

Author – Amy Davidson

The tallest flowering plant in the world is the mighty Mountain Ash (Eucalyptus regnans).  Regularly growing to 85m tall, the Mountain Ash is a straight trunked tree with grey bark and a stocking of rough brown bark at its base.

The trees grow in pure stands in wet forest with a rainforest understorey of ferns.  Despite the size of the tree, the flowers and leaves are on the smaller size for eucalypts growing to 1cm and 9-14cm respectively.


The Victorian botanist Ferdinand von Mueller described the species in 1871 using the Latin regnans, meaning ‘ruling’, as the species epithet.  The Mountain Ash was also the tallest of all trees on earth; however, that crown now belongs to the Giant Sequoia thanks to appalling logging practices in Tasmania and Victoria that saw the felling of our tallest old growth forests (some of the felled trees recorded an incredible height of 130 + metres).


The tallest living Mountain Ash today is the 99.82-metre-high Tasmanian Centurion. The tallest Mountain Ash growing on the mainland in Kinglake (91.6m) was destroyed by the Black Saturday bushfires in 2009.


The majority of the endangered Leadbeaters Possum lives in Mountain Ash forest in the central highlands of Victoria. Koalas, wedge-tailed eagles, black cockatoos and yellow-bellied gliders also use the forests for habitat.


Mature Eucalyptus regnans forests have been found to store more carbon than any other forest known – another reason for leaving these giants to grow. #landarch #plantoftheweek

Leave a Reply