River red gum (Eucalyptus camaldulensis)

Description

Eucalyptus camaldulensis, the river red gum, is a tree of the genus Eucalyptus. It is one of around 800 species within the genus. It is a plantation species in many parts of the world, but is native to Australia, where it has the most widespread natural distribution of Eucalyptus in Australia, especially beside inland water courses. It is named for a private estate garden near the Camaldoli monastery near Naples (L'Hortus Camaldulensis di Napoli), from where the first specimen came to be described. Material from this tree was used by Frederick Dehnhardt, Chief Gardener at the Botanic Gardens in Naples, to describe this species in 1832. It is a familiar and iconic tree seen along many watercourses right across inland Australia. The tree produces welcome shade in the extreme temperatures of central Australia, and plays an important role in stabilising river banks. The River Red Gum grows to 45 metres (148 ft) as a tall, frequently straight tree, but can develop a more twisted habit in drier conditions. It has smooth bark to the smaller branches ranging in colour from white and grey to red-brown, frequently with loose basal slabs in the lower trunk, and which it sheds in large plates or flakes or short ribbons. The tree has a large, dense crown of long and narrow adult leaves, lanceolate or infrequently falcate in shape, 5 to 30 centimetres (2.0 to 11.8 in) long by 0.7 to 3.2 centimetres (0.28 to 1.26 in) wide, and grey to grey-green on both surfaces. Side veins are prominent and usually at 45° to the leaf mid-rib, and oil glands are numerous and located separate to the veins. Its inflorescences comprise umbels of 7 to 11 flower buds located at the junction of leaves and stem, with the buds being of ovoid or globular shape and 0.6 to 1.1 centimetres (0.24 to 0.43 in) long by 0.3 to 0.6 centimetres (0.12 to 0.24 in) wide. Buds are green to yellow or cream, and have a prominent tip beak. Flowers are white to cream, and have been recorded in bloom within the range from June through to March. The fruit (gum-nuts) are brown, hemispherical in shape, 0.2 to 0.5 centimetres (0.079 to 0.197 in) long by 0.4 to 1.0 centimetre (0.16 to 0.39 in) wide, with a highly raised end-disk and 3 to 5 valves strongly exserted. River reds and many other eucalypts have an ominous nickname, "widow maker", as they have a habit of dropping large boughs (often half the diameter of the trunk) without warning. This form of self-pruning may be a means of saving water or simply a result of their brittle wood. This is also an efficient way of attracting wildlife that live in the holes formed, which gives the red gum a source of natural fertiliser