Blackbutt is the name given to two different species of eucalypt. They both belong to the myrtle family. The name ‘blackbutt’ comes from the dark grey trunk and the fact that the trunks become blackened after bushfires. The tree itself is very resistant to fire. The blackbutts are characterised by rough, dark grey, fibrous bark, glossy adult leaves, flattened peduncles (flower stalks) and somewhat large buds and fruit.
Eucalyptus pilularis (pilularis is Latin for ‘a small pill’ and refers to the fruit) is a medium to tall forest tree occurring naturally in a narrow coastal band from south of Bega, in far south-eastern New South Wales, north to Fraser Island in south-eastern Queensland. It may grow to 70 metres but is generally between 20 and 50 metres tall. It is well regarded for the high quality of the timber and its rapid growth and is one of the most important timber trees of eastern Australia. One of its uses is for house construction. Blackbutt is also a koala forage tree. The bark is rough on the lower trunk but smooth on the upper trunk and branches. The lance-shaped leaves are dark and glossy on the upper surface and paler underneath. The buds occur in clusters of from 7 to 15. The flowers are around 1.5cm in diameter and the gum nuts are almost spherical. This eucalypt has been planted with success in many overseas countries. Propagation is by seed.
Eucalyptus patens is also known as the West Australian Blackbutt, yarri or Swan River blackbutt. It is endemic to the south-west of Western Australia and is usually found in conjunction with Eucalyptus marginata (jarrah) or Eucalyptus diversicolor (karri) in moister parts of the forests of the south-west. Smaller amounts also appear from east of Perth to Albany. It is usually a tall tree up to 45 metres in height with a relatively large, straight trunk. Its form can be very ordinary on poor soil. The grain is interlocked which can make it difficult to work.
In Western Australia, the blackbutt is in short supply. As this timber is more common in old growth forests, it is now off limits for production purposes unless it has been salvaged or cultivated. It is not a hard tree to propagate and can be grown in conditions and areas well outside its natural parameters. The timber is an attractive yellow to honey colour, and is particularly favoured for panelling and flooring, being hard and durable. Under cultivation, eucalyptus patens can reach 31 metres in 35 years. It is one of the most non-flammable timbers in the world. The flowering season is from November to February. Stalked buds are arranged in clusters of 7 to 13 and the flowers are white.