Narrow-Leaf Orites (Orites revolutus)

Orites revolutus, known as the Narrow-leaf Orites, is a slow-growing shrub species endemic to Tasmania, Australia’s alpine and sub-alpine heaths and woodlands. It is extensive on mountain plateaus at altitudes ranging from 700 to 1300 m. It occurs in rocky areas of better-drained soil and may be present on dolerite and sedimentary substrates.

Orites revolutus is 1 of 9 species in the genus Orites, a member of the Proteaceae family. Seven species are endemic to Australia, and only 4 in Tasmania. The remaining two species reside in the Chilean Andes and Bolivia. Recent phylogenetic work suggests the genus Orites spread over the Gondwanan continent from South America to Australia during the Paleogene, reaching Australia by the Early Oligocene. Fossils of Orites revolutus indistinguishable from contemporary specimens have been recorded in Early Pleistocene sediments from western Tasmania, suggesting the species is at least this old.

The mean annual temperature within the plant’s range hovers around 8 °C, and rainfall tends to be as high as 1700 or even 2000 mm annually. Orites revolutus can be seen at many localities within the state, including the Hartz Mountains, Mount Field, Cradle Mountain-Lake St Clair and Ben Lomond National Parks, and Wellington Park near Tasmania’s capital city of Hobart.

Here is some useful plant-growing information about Orites revolutus, including tree height, spread, preferred soil type and pH.

Tree Height and Spread:

Orites revolutus typically grows to 0.5 to 1.5 meters with a spread of 1 to 1.5 metres and has an erect, woody shrub growth habit. Its relatively compact size and shape make it a good choice for small garden areas and landscaping applications in locations at elevation and with a cold climate.

Preferred Soil Type and pH:

Orites revolutus prefers well-drained soils that are acidic to slightly alkaline, with a pH range of 5.5 to 7.5. The tree grows best in well-drained soils rich in organic matter and has good water retention capabilities. It is not drought or heat tolerant and requires a cool aspect in most mainland garden settings. Orites revolutus namesake revolute leaf margins are very likely an adaption to the harsh growing conditions of its range, presumably adding structural integrity to leaves often exposed to frost, sleet and driving wind, and very high UV levels.

Climate and Sunlight Requirements:

Orites revolutus is native to alpine cool temperate climates and is adapted to the cool and humid conditions of the wet sclerophyll forests, alpine heaths and woodlands of Tasmania. The shrub prefers areas with frigid winters and cool summers and can be grown in full sun. Areas such as the NSW alpine region, the Brindabellas and southern ACT, the Southern Highlands and the Blue Mountains, the Southern and Central Tablelands and northeast Victoria are ideal locations for this species to thrive on the mainland. The Narrow-leaf Orites tree may require protection from direct sunlight during summer and high temperatures on the continent to prevent leaf scorching and stress.

Propagation and Pruning:

Orites revolutus can be propagated by seed or cuttings, although the latter method is generally more successful. The shrub is slow-growing and can take several years to reach maturity. Once established, the shrub requires minimal maintenance and pruning. However, occasional pruning may be necessary to remove dead or damaged branches or to maintain the shrubs’ growth habit.

Pests and Diseases:

Orites revolutus is generally resistant to most pests and diseases. However, the tree may be susceptible to scale insects and aphids, which can be controlled with insecticidal sprays or by introducing natural predators such as ladybugs or lacewings. The tree may also be susceptible to Phytophthora, root rot and other fungal diseases, particularly in poorly drained or waterlogged soils.

Uses:

Orites revolutus is rare in cultivation on the mainland but has a high potential for its ornamental value due to its growth habit and attractive needle-like foliage. The tree is well-suited for small gardens and landscaping applications and can be used as a specimen shrub in areas with cooler climates.

Orites revolutus is a slow-growing, narrow, erect shrub species well-suited for small gardens and landscaping applications. It prefers well-drained, slightly acidic soils with good water retention capabilities and is adapted to cold and humid temperate climates. The shrub is relatively low-maintenance but may require occasional pruning to maintain its growth habit. It is generally resistant to most pests and diseases and is primarily grown for its ornamental value.