This fabulous tree is my absolute favourite tree going. From the orange-salmon pink bark that feels like concrete rather than wood to the fact that this tree looses its bark once a year, I just find it an awesome species, if a little weird to my English eyes on first coming across it.

Angophora costata is a large tree that has a wide, spreading canopy. It can reach a height of 15-25 metres. The bark is quite gnarly and crooked, with the wood being rather brittle. The bark can range in colour from a pale grey, pink, orange and almost purple depending on the age of the bark, which is shed in large flakes annually in spring. Trees can loose limbs, with the butt of these fallen branches forming a callused bump, adding to the character of these trees.

The genus Angophora is in the Myrtaceae family. As usual, I like to give the meaning of the binomial plant names. Angophora comes from two Greek words, ‘angeio’ means vessel or goblet, while ‘phora’ means to bear or carry, both parts referring to the capsules (fruit) which are shaped like goblets. Costata is the Latin word for ribbed, which also refers to the capsules that have ribs on the outside. Kajimbourra is an Aboriginal name for the tree from the Sydney area.

This species shows heteroblasty, meaning the juvenile leaves are different to the adult leaves. Juvenile leaves are in an opposite arrangement and elliptic in shape. They are 13 cm long by about 6.5 cm wide. Adult leaves are also have an opposite arrangement. They are lanceolate or sometimes falcate in shape. The leaves have clearly visible veins on them and are paler on one side.

The flowers appear in terminal inflorescences, usually flowering between October and December, lasting until January. The individual flowers are white and quite showy. They are approximately 2 cm wide with five tooth-like sepals and semi-circular petals. There are a large number of stamens. The following fruit are ovoid to campanulate in shape to 2 cm in diameter by 2 cm long. The capsules have ribs on the outside.

The habitat of the Sydney red gum is dry sclerophyll open forest. It appears in wet alluvial valleys and exposed valley tops with poor sandstone soils. In my research, it says that only Eucalyptus heamastoma (Scribbly gum) is a hardier tree in these exposed conditions. You can often find this tree growing in rock crevices, which fascinates me-it gives the tree extra character. The rainfall ranges from 635-1520mm per year in the range of the tree.

The distribution of this tree is mainly along the coastline of the New South Wales and southern Queensland. They extend inland towards Bathurst in the Blue Mountains to the west of the Sydney basin.

The tree readily propagates from seed, usually germinating within a week. The seeds don’t need any special treatment to allow germination to take place. When the seedlings reach a height of around two centimetres, they should be transplanted into larger pots until they are ready for planting into the landscape.

The use for this tree is really only for use in a very large garden or landscape like a public park, due to the size. Where they are best is in their natural habitats, or where there is plenty space for native plantings to provide native wildlife with food and shelter.

References

• https://www.anbg.gov.au/gnp/gnp8/ango-cos.html. Accessed 29/03/24
• Https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/nswfl.pl?page=nswfl&lvl=sp&name=angophora%7ecostata. Accessed 29/03/24
• Https://resources.austplants.com.au/plant/angophora-costata. Accessed 09/07/21