Eucalyptus camaldulensis, commonly known as the river red gum, is a tree that is endemic to Australia. It has smooth white or cream-coloured bark, lance-shaped or curved adult leaves, flower buds in groups of seven or nine, white flowers and hemispherical fruit with the valves extending beyond the rim. A familiar and iconic tree, it is seen along many watercourses across inland Australia, providing shade in the extreme temperatures of central Australia. Description Eucalyptus camaldulensis is a tree that typically grows to a height of but sometimes to and often does not develop a lignotuber. The bark is smooth white or cream-coloured with patches of yellow, pink or brown. There are often loose, rough slabs of bark near the base. The juvenile leaves are lance-shaped, long and wide. Adult leaves are lance-shaped to curved, the same dull green or greyish green colour on both sides, long and wide on a petiole long. The flower buds are arranged in groups of seven, nine or sometimes eleven, in leaf axils on a peduncle long, the individual flowers on pedicels long. Mature buds are oval to more or less spherical, green to creamy yellow, long and wide with a prominently beaked operculum long. Flowering mainly occurs in summer and the flowers are white. The fruit is a woody, hemispherical capsule long and wide on a pedicel long with the valves raised above the rim. The limbs of river red gums, sometimes whole trees, often fall without warning so that camping or picnicking near them is dangerous, especially if a tree has dead limbs or the tree is under stress. Taxonomy and naming Eucalyptus camaldulensis was first formally described in 1832 by Friedrich Dehnhardt who published the description in Catalogus Plantarum Horti Camaldulensis. Seven subspecies of E. camaldulensis have been described and accepted by the Australian Plant Census. 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. The subspecies are: Eucalyptus camaldulensis subsp. acuta Ian Brooker & M.W.McDonald has mature flower buds with a pointed operculum long and erect stamens and broadly lance-shaped or egg-shaped juvenile leaves; Eucalyptus camaldulensis subsp. arida Ian Brooker & M.W.McDonald has bluish green adult leaves with only a few veins and mature flowers buds with a curved to rounded operculum long; Eucalyptus camaldulensis Dehnh. subsp. camaldulensis