Eucalyptus radiata

Narrow-leaved Peppermint

Family: Myrtaceae

A tree, growing to a height of 50 m in forest and woodland.

Usually found in cooler or wetter habitats in New South Wales, south from near or just over the Queensland border, along the tablelands / and highlands of the coastal areas, to the Wombat State Forest and Great Otway National Park and ranges of South Gippsland in Victoria and into central Victoria. It also occurs in Tasmania where it is restricted to the catchment of the Forth River.

It can be found on a range of soils – sandy to shale and basalt. It forms a dominant part of some mapped vegetation communities in NSW.

Bark is rough, finely fibrous or flaky grey (peppermint-bark) on the trunk and branches, usually smooth grey bark on branches thinner than 80 mm. The bark sheds off when rubbed with the hand (a useful identification feature).

Juvenile and coppicing regrowth is distinctively sessile, narrow lance-shaped to linear leaves to 100 mm long to 20 mm wide, paler on the lower surface and arranged in opposite pairs, with a very strong peppermint odour.

Adult leaves are the same shade of green on both sides, lance-shaped to curved or almost linear, to 120 mm long and to 15 mm wide, tapering to a petiole to about 15 mm long, also with a pungent peppermint odour (very useful for identification).

The flower buds are arranged in clusters (umbellasters) in leaf axils on peduncles to 12 mm long. In this species, at least 11, and up to 20 or so buds, are produced in each umbellaster – the latter a useful identification feature. Mature buds are club-shaped, to 5 mm long and to 3 mm wide with a rounded or conical operculum / calyptra that is shorter and narrower than the floral cup at the join.

Flowering occurs from October to January and the flowers are white and very showy.

The capsule is woody, cup-shaped, hemispherical or shortened spherical capsule to 6 mm long and to 7 mm wide with the valves enclosed or near rim level.

In the garden

A nice-enough tree in a garden but can grow large. They are some grandiose specimens in places such as the Southern Highlands of NSW, which reach 40 metres in height (Exeter, Bundanoon, Penrose etc). But on sandy soils, they are usually shorter.

Has nice narrow-weeping foliage and the fibrous bark can be covered in green lichen in moist areas. A very hardy tree. Not suited to small residential gardens. Would be a nice specimen tree in a park or paddock. Not overly fussy of soil type. Can be grown on flat of sloping areas.

Eucalypts 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

Eucalyptus can be propagated by seeds which is most common method or grafting.
Cuttings are difficult to start, but can be used in some species.

For further information refer to: http://anpsa.org.au/APOL2007/sep07-s1.html

Other information

There are two subspecies currently recognised in NSW:
Eucalyptus radiata subsp. radiata
• Eucalyptus. radiata subsp. sejuncta – which grows on the Northern Tablelands and has broad lanceolate leaves

Some botanists also recognise subsp. robertsonii which grows in the Southern Tablelands of NSW and Victoria.

Eucalyptus radiata has six known chemotypes of essential oil.

Eucalyptus is one of three similar genera that are commonly referred to as “eucalypts”, the others being Corymbia and Angophora.
Refer to these two links for more clarification:
http://anpsa.org.au/eucal1a.html
http://anpsa.org.au/APOL2/jun96-5.html

Regenerates after fire from lignotuber and epicormic growth as well as seed.

Eucalyptus – from Greek, eu, “well” or “true” and calyptus, referring to the calyptra (καλύπτρo) or operculum, which is a bud cap or covering which covers the developing flowers. The calyptra is a fusion of petals and/or sepals and is shed when the flower opens, leaving a flower with many stamens (staminate) surrounding one female part (carpel).
radiata – Latin “radiating”, referring to the flower bud clusters which have many buds splaying out around a somewhat-circular shape.

Not considered to be at risk in the wild.

“Field Guide to Eucalypts Vol 1 South Eastern Australia’ M.I.H.Brooker and D.A.Kleinig. Blooming Books.
https://en.wikipedia.org/wiki/Eucalyptus_radiata
https://apps.lucidcentral.org/euclid/text/entities/eucalyptus_radiata_subsp._radiata.htm
https://en.wikipedia.org/wiki/Eucalyptus
https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Eucalyptus~radiata

By Jeff Howes