Eucalyptus camaldulensis Rostrata

Eucalyptus camaldulensis is an Australian species that is tall and grows very quickly. Widespread throughout Australia, it has also become very common around the Mediterranean. Its decorative bark and slightly bluish evergreen foliage make it popular as an ornamental tree. Undemanding in terms of soil, as long as it is not chalky, it grows in the sun. While it appreciates humidity, it is also capable of withstanding dry spells. Given its size, it is best reserved for large gardens, where it will make a beautiful specimen in isolation.

The Eucalyptus is a tree of the Myrtaceae family, like the Feijoa, Callistemon or Myrtle, with characteristic flowering of this family. The genus Eucalyptus, native to Australia, has more than 800 species, including the tallest deciduous trees in the world (E. regnans). The species E. camaldulensis is one of those with the widest distribution in Australia (rostrata is an old name related to the particular shape of the flower bud). It is a large tree that can exceed 40m (131 ft 2 in) in height, commonly growing along watercourses in semi-arid regions, hence its common name Red River Gum. The epithet "red" refers to the colour of its wood, which is used locally to make fence stakes, and also used by cabinetmakers for its unique colour. In Australia, it is a useful tree, providing timber and firewood, used for making pulp and dye with its red gum, and essential oils. Its bees produce highly sought honey.
Introduced to Europe 2 centuries ago thanks to seeds collected in 1817 in New South Wales, it is now the most widespread species in the Mediterranean, where it has adapted well, proving its good resistance to drought once established. It can reach 20 to 30m (65 ft 7 in to 98 ft 5 in) in height and 15 to 20m (49 ft 2 in to 65 ft 7 in) in width, developing a massive trunk over 1m (3 ft 4 in) in diameter at maturity which is straight or slightly twisted. Its bark is truly decorative, predominantly a light, grey-white, adorned with grey, green, and red, and regularly exfoliates. Rain particularly highlights these colours, making the trunks shiny.
Its evergreen foliage, ranging from green to grey-blue, takes on a different form depending on its maturity: the juvenile leaves are opposite, petiolate, oval to lanceolate, measuring about 8 to 18cm (3.1 to 7.1 in) long and 1.3 to 2.5cm (0.5 to 1 in) wide. The adult foliage is lanceolate to sickle-shaped and each leaf measures 5 to 30cm (2 to 11.8 in) long and 1 to 3cm (0.4 to 1.2 in) wide, also petiolate but alternately arranged on the branches.
Flowering occurs in March-April in the form of umbel inflorescences consisting of 7, 9, or 11 small flowers, with white to yellow stamens. Relatively inconspicuous compared to the tree's vegetative mass, it is primarily of interest for its honey production. Fruits that are small hemispherical capsules containing tiny brown-yellow seeds then develop. This species will self-seeding abundantly.
The Eucalyptus camaldulensis has great adaptability. It grows in a wide variety of soils, only disliking overly active limestone. Ideal for stabilizing riverbanks, it also withstands dry conditions quite well after the first few years of growth. Growing in full sun, it is moderately hardy and can withstand dry, brief cold spells of around -10°C (14 °F) under good conditions. It is also a tree that tolerates pruning very well, including severe pruning. A large trunk cut in summer will produce a clump of shoots before winter.

Eucalyptus camaldulensis makes a beautiful specimen to place in a large garden. It adds an undeniable touch of exoticism to the landscape, casting a light shade. It is mainly used in isolation due to its imposing size and because it competes strongly for water with other nearby plants (it is also suspected of producing inhibitory root substances towards certain other plants). It is perfect as a background plant in a large, exotic-inspired garden, where other Myrtaceae such as Metrosideros, with vibrant red-toned flowers, can also be found. A flowering Pomegranate tree, like Punica granatum California Sunset would also be well-suited in this type of setting.