Growing in swampy or waterlogged soils, it is up to 30 m (100 ft) high with thick spongy reddish-brown bark and dark green broad leaves, which help form a dense canopy.

The long irregular branches spread laterally, and form a dense canopy with the broad green leaves.

Adult leaves are broadly lanceolate to ovate, green and glossy, and with closely spaced "feather-like" side veins running at greater than 45° angle to the main midrib.

[5] The buds measure 2 by 0.8 cm (0.79 by 0.31 in) wide and are distinctive in that the operculum has a prominent long beak,[6] making them fusiform (spindle-shaped).

[5][3] The bangalay (E. botryoides) is similar in appearance, but its flower buds are smaller with a conical operculum and only grow in groups of seven.

[6] Specimens of E. robusta were first collected by First Fleet surgeon and naturalist John White, and the species description was published by James Edward Smith in his 1793 collaboration with George Shaw, Zoology and Botany of New Holland.

Smith gave it the specific epithet robusta ("robust") in reference to the size and strength of the full-grown tree.

[4] Eucalyptus robusta often hybridises with forest red gum (E. tereticornis), the resulting plants having been given the name E.

[4] The species has been formally assessed for the IUCN Red List as "Near Threatened (NT)" as its population is thought to have declined by 25.7% over the previous three generations.

[5] Eucalyptus robusta appears to be one of several key species of eucalypt for the koala in the Shire of Noosa in Queensland.

[16] It is a keystone species on the New South Wales Central Coast and Illawarra regions, where it is one of few reliable winter-flowering plants.

[17] Insects, such as psyllids and Christmas beetles from the genus Anoplognathus and the eucalyptus chafer (Xylonichus eucalypti) commonly eat the leaves.

[12] Eucalyptus robusta plantations in Madagascar are host to prolific numbers of mushrooms, some of which are edible and widely consumed.

[20] It can flower in its third year of growth in cultivation in optimal conditions,[12] and its timing makes it an important source of food during autumn and winter.

[23] It has been widely grown in plantations outside Australia, including Argentina, Brazil, Cameroon, Chile, China, Colombia, Comoros, Congo, Costa Rica, Democratic Republic of Congo, Ethiopia, Fiji, Honduras, Hong Kong, India, Kenya, Madagascar, Malawi, Malaysia, Mauritius, Mexico, Mozambique, Papua New Guinea, Paraguay, Philippines, Puerto Rico, South Africa, Sri Lanka, Taiwan—Republic of China, Tanzania, Uganda, Zanzibar, and the United States of America,[12] where it has been grown in Hawaii, southern Florida, southern California and Puerto Rico.

[23] In cultivation, E. robusta grows to altitudes of 1,600 metres (5,200 ft), withstanding average minimum temperatures of 3 °C (37 °F) and maxima of 35 °C (95 °F).