Angophora costata

Smooth-barked Apple / Sydney Red Gum

Family: Myrtaceae

A large tree (rarely a mallee), reaching up to 25 m tall.
It has a primarily coastal occurrence in NSW, extending down to the south coast, with some disjunct records in Victoria (north of Melbourne). It extends northwards to north and west of Tamworth, and Armidale, into Queensland and up in disjunct patches, to the west of Townsville. It is a weed in New Zealand.
It is typically found on sandstone and sandy areas in dry sclerophyll woodlands and forests, in gullies and creeklines, and on higher ground. It can be found on heavier shale soils in some instances and forms part of tall forests in some areas. It can also be found growing as a mallee in coastal shrubland.

The bark is smooth and red-salmon to brown-grey-purple and very conspicuous, making it an easily identifiable tree. It has an annual shedding process where large amounts of thin plates are shed. Old trees typically have many dimples, cortorted branches and large bowl-like swellings (hence the reference to “apple” in the common name).

The juvenile foliage / coppicing growth is usually purple-red to begin with, changing to mid-green, lanceolate, to about 10 cm long and hairless. Leaves are arranged oppositely.

The adult leaves are opposite, lanceolate and usually very straight, to about 20 cm long and up to 7 cm wide with an acuminate apex, glabrous and discolorous, mid to dark green – not usually glossy and with not much odour.
The primary inflorescence of “eucalypts” (Angophora / Corymbia / Eucalyptus) is an umbellaster (an umbel-like cluster of flowers). In Angophora, the flower still retains its small and free petals and sepals. They are not fused into a calyptra / operculum which is shed, as in Eucalyptus and Corymbia.
Flower buds are produced in umbellasters of 7, ovoid to globose to about 10 mm long and 11 mm wide. The petals are very short – about 5 mm long. The buds are usually green in colour.
Flowering can be observed in October to January and individual flowers are up to 1 to 2 cm across, bright cream to white. Like Corymbia spp., Angophora spp. have flowers positioned beyond the foliage at the terminals.
The capsules are ovoid to campanulate with conspicuous ribs and teeth and are comparatively large, to 20 mm long by 20 mm wide with a flat disc.

In the garden

A very popular tree in landscaping and bushland revegetation projects (where habitat is suitable). It is desired for its red-salmon trunk and smooth-gum like appearance and lends to feature trees in modern landscapes. It can get large and so not suited to small residential gardens. Many trees exist in residential backyards as remnants. A note of caution: they do have a reputation for falling once the surrounding soil is altered and trees are isolated in gardens or streets. However, some trees in Sydney backyards and streets are very old and have stood the test of time.

A reliable tree and easy to grow, even on heavier soils. It does best on a sandy soil but will establish and grow well on a clay soil.

Very attractive flowers in Summer. Good shade tree. It could be trained as a mallee once established by frequent cutting and pruning of main stems.

Angophora spp. can suffer problems from, caterpillars, leaf eating beetles, psyllids and borers to name a few. In undisturbed conditions, the numbers of eucalypt-feeding insects and their predators and parasites are in balance, so that they rarely cause tree death and most trees quickly recover from attack. In a home situation nature can get out of balance.

Propagation

Seed would work best.
Cuttings are difficult to start, but can be used in some species.

Other information

Angophora is one of three similar genera that are commonly referred to as “eucalypts”, the others being Corymbia and Eucalyptus.

There are currently two subspecies recognised in NSW:
• subsp. costata – no hairs on the base of the flower and smaller fruit
• subsp. euryphylla – hairs on the base of the flower and larger fruit (occurring only around the Putty to Wollombi district).

Regenerates very quickly after fire from lignotuber and epicormic shoots with coppicing growth which is dull red-purple in colour

Angophora – from the Greek word Angeio (αγγειο) which means “vessels” such as “vases” or “pots”, and -phora “bringing forth” or “carrying”, relating to the vase-like fruits (capsules) of many species.

costata – Latin – with ribs, referring to the surface ribs or raised lines on the capsules.

Not considered at risk in the wild.

https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Angophora%7Ecostata
https://en.wikipedia.org/wiki/Angophora_costata
https://www.gardeningwithangus.com.au/angophora-costata-sydney-red-gum/

By Dan Clarke