Eucalypts – gum trees – dominate the landscape of the Reserve. They play a role in providing food and shelter for wildlife: nectar, leaves and seed as food, and hollows as shelter. Around a third of the mammal population and around 14% of Australia’s birds use eucalypt tree hollows for shelter or nesting (Wrigley & Fagg, 2010). Tree hollows are an important part of a healthy ecosystem.
Eucalypt species are all related and it can be difficult to differentiate one from another. There are over 900 species of eucalypts in Australia (Boland et al., 2006) and the Reserve is home to a range of primarily rough barked species of trees and the multi-trunked form, the mallee.
Most eucalypts in the Reserve have white flowers and a great many flower during spring and summer. Identified varieties include the manna gum, messmate (click here), yertchuck, narrow-leaved and broad-leaved peppermint (here) and silver leafed stringybark (see this posting.)
Boland, B.J., Brooker, M.I.H., Chippendale, G.M., Hall, N., Hyland, B.P.M., Johnson, R.D., Kleinig, D.A., McDonald, M.W. & Turner, J.D. Forest Trees of Australia, CSIRO Publishing: Collingwood.
Costermans, L (2009) Native Trees and Shrubs of South-eastern Australia, Reed New Holland: Sydney
Wrigley, J. & Fagg, M. (2010) Eucalyptus A Celebration, Allen & Unwin: Crows Nest.
Eucalyptus radiata, Narrow-leaved peppermint
Can be a tall tree in forests and a medium-sized tree in more open sites, 12 – 45m (Costermans, 2009). Its bark distinguishes it from close rough-barked neighbours in the Reserve, being finely fibrous and finely longitudinally fissured, grey or grey-brown (Brooker & Kleinig, 1999) although never stringy (Costermans, 2009). Its leaves are long and narrow (around 1.5 cm wide), veins are faint and leaves change shade of green from a brighter green when juvenile to a dull grey-green when adult (Costermans, 2009). They also have the characteristic peppermint smell.
Eucalyptus dives, Broad-leaved peppermint
A small to medium tree (8-25m) (Costermans, 2009), this eucalypt is quite similar to e.radiata. Its leaves are broader, around 3cm, but begin a grey-green or glaucous colour, they are ovate and much larger in the juvenile form at 15 X 7cm (Brooker & Kleinig, 1999). Their veins are more distinct than is the case in the narrow-leaved peppermint. Like the narrow-leaved peppermint, there are more than seven buds on each cluster and the buds are club shaped, although the caps are rounded (and in e.radiata they can be slightly peaked (Brooker & Kleinig, 1999)). Also like the narrow-leaved peppermint, this one has pear or cup shaped fruits, which are small, with small valves at around rim level.
The tree flowers (white) September/October to December/January (depending on which field guide you’re reading; although, Costermans(2009) points out that there will be variations depending on environmental factors such as climate, soil and forest density.)
These varieties of eucalypt are also likely to hybridise.
Further identifying information can be found at the Yarra Ranges Plant Directory for Eucalyptus radiata ssp. radiata.
Also, see this posting for identifying differences between the two peppermints.
Eucalyptus obliqua, Messmate (stringybark)
This is a rough barked eucalypt, medium to tall (13-70m), with thick fibrous bark persistent to the smaller branches, brown to pale brown colouring. The leaf shape shifts from small, broadly ovate, generally in opposite pairs, to alternating, quite large (19 X 8cm) and adopting the species’ oblique connection to the leaf’s base. They also go through a stage where they are held horizontally and are, at first, differently coloured top and bottom (Brooker & Kleinig, 1999). Adult leaves are alternating, asymmetrical, coloured the same on top and bottom, sub-glossy dark-green, around 9 to 16cm long and veins are distinct (Costermans, 2009).
Flowering occurs December to March (Brooker & Kleinig, 1999). Flowers are white/cream and there are lots of them. Buds occur in the leaf axils, are club-shaped with a rounded cap with a small point, and occur in clusters of 7 to 15 on stalks (Costermans, 2009). Fruit is wine-glass shaped, with a stem, and valves are enclosed.
Costermans (2009) points out that this was the first eucalypt described (in 1788) and was collected from Tasmania.
Another identification source can be found in the Yarra Ranges’ Plant directory for Eucalyptus obliqua. More locally, another source is the Traralgon South and District Environmental Action samples, as well as the Morwell National Park’s images.