Eucalyptus sclerophylla

Hard-leaved Scribbly Gum, Narrow-leaved Scribbly Gum, Snappy Gum

Family: Myrtaceae

A tree, growing up to 20 metres tall. Around Sydney it often occurs on the higher ridges, where the soil is drier and less fertile as well as in vegetation types such as Castlereagh Scribbly Gum Woodland. Further afield, it ranges north from Jervis Bay, Pokolbin in the Hunter Valley.

Smooth barked, with shedding bark of white or grey. Scribbles often found on the bark.

Adult leaves to 16 cm long, to 4 cm wide, lanceolate to falcate, grey-green in colour, on both sides of the leaf and with a strong smell.

White flowers form between November and February. The flower buds are in umbellasters of 11 or more, in leaf axils, to 5 mm long and 3 mm wide, with a hemispherical rounded operculum / calyptra.

The capsule is cup-shaped, hemispherical to spherical, to 7 mm long and to 5 mm wide with the valves near rim level. The top of the capsule is red-brown when ripe.

In the garden

Not an overly common tree in cultivation but very useful on sandy soils. Is seen as a street tree in some places. Would be suited to open gardens on sandy soils and they can be kept as a mallee. In their natural habitat, they are usually not overly large, but should best be avoided in small gardens.

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: h

ttp://anpsa.org.au/APOL2007/sep07-s1.html

Other information

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

There have historically been 5 scribbly gum taxa recognised in NSW. Recent studies have lumped these taxa into 3 entities as follows:
Eucalyptus haemastoma
– Eucalyptus racemosa subsp. racemosa
– Eucalyptus racemosa subsp. rossii

However, this revision was not accepted at a Commonwealth level.

Genetic research still continues as the taxa are known to intergrade with likely hybridisation.

At the time of writing, it seems this species has been absorbed into Eucalyptus racemosa. However, this is still in a state of flux.

Not considered at risk in the wild.

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).
sclerophylla – is from the Ancient Greek words skleros (Σκληρός) meaning “hard” or “tough” and phyllon meaning “leaf” referring to the toughness of the leaves. There is a type of leaf tissue referred to as “sclerenchyma” which a lot of Australian natives possess.

“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_sclerophylla
https://en.wikipedia.org/wiki/Eucalyptus
https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.plpage=nswfl&lvl=sp&name=Eucalyptus~sclerophylla

By Jeff Howes