Eucalyptus camaldulensis, commonly known as the river red gum,[3] is a flowering plant in the family Myrtaceae, and is endemic to Australia.

The most variable character is the shape and size of the operculum, followed by the arrangement of the stamens in the mature buds and the density of veins visible in the leaves.

[23] Finally in 1934, William Blakely recognised Dehnhardt's priority and the name E. camaldulensis for river red gum was accepted.

[26][27] Eucalyptus camaldulensis grows under a wide range of climatic conditions from tropical to temperate, but the main areas are characterised by 5 to 20 frosts in winter and high summer temperatures.

Due to the proximity to these watercourses, river red gum is subject to regular flooding in its natural habitat.

[32] However, the Murray–Darling Basin Commission has recognised the importance of snags as aquatic habitat, and a moratorium on their removal from the Murray River has been recommended.

[33] Hollows start to form at around 120–180 years of age, creating habitat for many wildlife species, including a range of breeding and roosting animals such as bats, carpet pythons, and birds.

[34] River red gums contribute to the provision of nutrients and energy for other species through leaf and insect fall.

[27] The tree's preferred habitat of floodplains and watercourses also gives it the role of flood mitigator, which slows silt runoff.

[35] The species, while native to parts of Western Australia, has become naturalised via garden escapees and introduction as a restoration plant; they are the subject of weed management programs.

[7] Its ability to tolerate drought and soil salinity, together with its prolific seed production, and capacity to reproduce when very young, mean that it is highly adaptable, and it has been declared invasive in South Africa, California, Jamaica, Spain, and Hawaii[36] The flower begins as an "invaginated receptacle".

This can occasionally lead to self-pollination, although the stigma does not become receptive until a few days after the operculum has been detached by the expanding stamens, and the flower's pollen has already been released.

There is some contention in this theory, however, where the CSIRO describes an experiment that demonstrated seeds were found to sink after only 36 hours.

Its leaves have appeared on Australian stamps[40][page needed] and is widely recognised due to its widespread range.

The use of the waterways for seasonal recreation also occurs within the habitat of the river red gum, again due their fundamental link to watercourses and floodplains.

[27] An image of The Old Gum Tree was engraved for a stamp in 1936 to commemorate the centenary of foundation of South Australia.

Lack of flooding in floodplain areas will change the suitability of river red gum habitat as a breeding ground and food source for other species.

[27] It has been recognised since around the early 1980s that managing water more effectively would ensure the maintenance of river red gum habitat.