Эвкалипт камальдульский: Описание и распространение.

Species of plant

Eucalyptus camaldulensis, commonly known as the river red gum, is a species of flowering plant in the family Myrtaceae, and is endemic to Australia. It is a tree with 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.

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.

Eucalyptus camaldulensis has the widest natural distribution of any eucalyptus species. It is commonly found along waterways and there are only a few locations where the species is found away from a watercourse. Subspecies acuta is common along rivers from south of Cape York Peninsula in Queensland to the north west slopes and plains of New South Wales but is absent from coastal areas and the arid inland. Subspecies arida has the widest distribution of the subspecies and is found in all mainland states except Victoria. It grows in arid regions but only where there is sufficient subsoil moisture. Subspecies camaldulensis is the dominant eucalypt along the Murray Darling river system and its tributaries. It also occurs on the Eyre and Yorke Peninsulas and Kangaroo Island in South Australia and in some locations along the Hunter River in New South Wales. It is the only subspecies in coastal Victoria. Subspecies minima is endemic to South Australia, where it grows in the northern Flinders Ranges and the northern Eyre Peninsula. 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. 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. River red gums contribute to the provision of nutrients and energy for other species through leaf and insect fall. This is especially important to the ecology in areas of low nutrients. lists E. camaldulensis as a weed in Portugal, Canary Islands, South Africa, Spain, Bangladesh, the United States, Ecuador, the Galapagos and other countries.

The flower begins as an "invaginated receptacle". The operculum, or cap, protects the interior of the flower bud, as the male and female parts develop. The male parts of the flower consist of the stamen, a slender filament, and the anther, two pollen sacs located at the top of the stamen. The anther sacs open into longitudinal slits to release their pollen. These filaments will extend to encircle the receptacle during flowering. The female parts of the flower, the ovaries, are contained in ovary chambers. These chambers are separated from the receptacle containing the male parts by a disc. From the top of the ovaries a structure called the style extends into the receptacle, to form the stigma. During flowering, pollen from the anthers can fall onto the stigma. 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. Fertilisation will therefore occur with other flowers on the same tree or other flowers on a different tree. Insects, birds, and small mammals help in the pollination of other flowers. while natural flooding occurs during winter and spring. 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.