Eucalyptus pilularis facts for kids
Quick facts for kids Blackbutt |
|
|---|---|
 |
|
| Scientific classification | |
| Genus: |
Eucalyptus
|
| Species: |
pilularis
|
| Synonyms | |
The Blackbutt (scientific name: Eucalyptus pilularis) is a type of medium to tall tree found only in eastern Australia. It has rough, greyish bark on the bottom half of its trunk. The top half has smooth bark that can be white, grey, or cream-coloured. Its leaves are long and narrow, and its flowers are white, growing in groups of seven to fifteen. The fruit looks like a small, round capsule.
Contents
What it Looks Like
The Blackbutt tree can grow very tall, sometimes up to 70 m (230 ft) high. It has a special kind of bark: the lower part of the trunk has rough, grey-brown bark that feels a bit like fibres. Higher up, the bark is smooth and can be white, grey, or cream. Sometimes, you can see wiggly lines on the smooth bark made by insects.
Young Blackbutt plants have stems that are almost square. Their young leaves are a dull green, paler underneath, and sit directly on the stem, often in pairs. These young leaves are shaped like a spear, about 55–130 mm (2.2–5.1 in) long and 10–36 mm (0.39–1.42 in) wide.
As the tree gets older, its leaves grow differently. Adult leaves are shiny green on both sides and are arranged one after another along the stem. They are shaped like a spear or slightly curved, about 75–170 mm (3.0–6.7 in) long and 12–32 mm (0.47–1.26 in) wide. They have a small stalk, called a petiole, about 8–22 mm (0.31–0.87 in) long.
The flowers grow in groups of seven to fifteen in the leaf axils (the spot where a leaf joins the stem). Each group is on a flat stalk, called a peduncle, about 8–20 mm (0.31–0.79 in) long. Each flower bud has its own small stalk, called a pedicel, about 2–7 mm (0.079–0.276 in) long.
Before they open, the flower buds are oval or spindle-shaped, about 6–10 mm (0.24–0.39 in) long and 3–5 mm (0.12–0.20 in) wide. They have a cap, called an operculum, that can be cone-shaped or pointed like a beak. Blackbutt trees usually flower from January to April or from October to December, and their flowers are white.
After flowering, the tree produces woody fruits called capsules. These are shaped like a half-sphere, a flattened sphere, or an oval. They are about 5–11 mm (0.20–0.43 in) long and 7–12 mm (0.28–0.47 in) wide. When the fruit opens, it has four parts, called valves, that are usually near the rim.
Tree Names and History
The Blackbutt tree was first officially described in 1797 by a scientist named James Edward Smith. He wrote about it in a publication called Transactions of the Linnean Society of London.
The scientific name pilularis comes from a Latin word meaning "a small pill." This refers to the shape of the tree's fruit. The first sample of this tree was collected near Sydney by a surgeon named Surgeon White.
Blackbutt belongs to the Eucalyptus genus. It's part of a group of eucalypts that have rough but not stringy bark. Their young leaves are large and grow opposite each other, while adult leaves are shiny green. The seeds of these trees are reddish-brown, smooth, and shaped like a pyramid.
Sometimes, Blackbutt can be mistaken for other trees like the Sydney peppermint (Eucalyptus piperita) or Sydney blue gum (E. saligna). However, you can often tell Blackbutt apart by the strong V-shape where its branches fork. Koalas love to rest in these V-shaped spots!
Where Blackbutt Trees Grow
Blackbutt trees are found in forests along the coast of eastern Australia. They grow from Eden in southern New South Wales all the way up to southeastern Queensland. They usually grow at low to medium heights above sea level. However, near Wauchope, they can be found at 800 metres (2,600 feet) high, where they are a very common tree.
These trees usually prefer sandy soils near the coast, but they can also grow well in clay and volcanic soils. They grow very large on drier slopes close to rainforests. Blackbutt trees need between 900 mm and 2000 mm of rain each year. The climate where they grow is often warm and humid. Even in the coldest month, the temperature usually stays between 5 to 10 degrees Celsius. In the hottest month, it's usually between 24 to 32 degrees Celsius. Sometimes, there can be frosts in areas away from the coast or at higher altitudes.
Other Trees Nearby
Blackbutt trees often grow alongside many other types of trees. In richer forests, you might find them with trees like Sydney blue gum, tallowwood, white mahogany, grey ironbark, red mahogany, coast grey box, brush box, and turpentine.
In drier areas, Blackbutt grows with trees such as spotted gum, Angophora costata, Sydney peppermint, and scribbly gum.
Blackbutt in Nature
Blackbutt trees are a very important part of the top layer, or canopy, of several endangered forest communities. These include blue gum high forest, Illawarra lowlands, bangalay sand forest, and grassy woodland. They provide shelter and habitat for many animals.
Timber and Its Uses
Blackbutt is a very important tree for the timber industry. Foresters (people who manage forests) like it because its wood is high quality, it grows quickly, and it's easy for new trees to sprout.
The wood is used for many things, such as:
- Making strong poles
- Railway sleepers (the wooden beams under train tracks)
- Flooring
- Building frames for houses
- Cladding (the outer layer of buildings)
- Joinery (making wooden joints)
- Lining boards
- Furniture
- Woodchipping
- Decking
The wood is quite heavy, weighing about 900 kg for every cubic metre. The sapwood (the outer, newer part of the wood) can resist tiny insects called lyctus borers. The heartwood (the older, inner part) is yellowish-brown to light brown.
Blackbutt wood has a coarse texture and is usually quite straight-grained, though it might have small "gum veins" (lines of dried sap). It's hard, strong, and tough, but it's not too difficult to work with. It dries slowly and is known for being quite durable. For example, Blackbutt timber was used for the flooring in Parliament House, Canberra.
Famous Blackbutt Trees
In Middle Brother National Park, there are two very old Blackbutt trees. One is called Benaroon, and it is 64 metres tall and 4.1 metres wide at chest height. Another tree nearby, called Bird Tree, is 69 metres tall and 3.59 metres wide at chest height.
There was once an incredibly tall Blackbutt tree near Bulli that was 85 metres tall before it was cut down.
Places Named After Blackbutt
Several places have been named after the Blackbutt tree:
- The towns of Blackbutt and Benarkin in Queensland.
- The nearby Blackbutt Range in Queensland.
- A nature reserve near Newcastle in New South Wales called Blackbutt Reserve.
- The suburb of Blackbutt in the Illawarra region on the South Coast of NSW. This area also has the Blackbutt forest reserve, which is the largest natural bushland reserve in the Illawarra.
Images for kids
-
A group of 5 spindle-shaped, beaked inflorescences
-
Blackbutt gumnuts
-
Blackbutt leaves
-
60-metre tall blackbutt near New England National Park, Australia
