Potentially a very tall tree, reaching 60 metres in some natural habitats. It has a sturdy straight trunk with continuous ‘stringybark’ (stringy / mahogany-like) with very small brown-mica flakes on the surface (which aids identification) and forms a lignotuber. This species usually has a broad symmetrical canopy in cultivation.
It grows on the NSW and Queensland coastal divisions, north from about the Gosford area, to Hervey Bay in Qld and including Fraser Island.
It forms a dominant component of many vegetation types in these areas, mainly wet and dry sclerophyll forest up to rainforest edges, on higher-fertility soils.
Eucalyptus spp. have simple and usually alternate adult leaves with juvenile leaves starting off opposite to alternate (disjunct). In this species, the juvenile foliage / coppicing growth is disjunct, ovate to elliptic and glossy green, to 11 cm long and 5 cm wide. The adult leaves are also disjunct, broad-lanceolate to 12 cm long and about 2.5 cm wide, green and glossy and discolorous.
The primary inflorescence of “eucalypts” (Angophora / Corymbia / Eucalyptus) is an umbellaster (an umbel-like cluster of flowers). In the flowers of Corymbia and Eucalyptus, the petals and sepals are fused into the distinctive calyptra / operculum (bud cap) which is shed when the flower opens (in some species, 2 bud caps (opercula) are shed). The flowers are conspicuously staminate – where many stamens are basically taking over the role of the petals, all surrounding one central carpel. In this species, the flower buds are arranged in leaf axils in umbellasters of 7-11 or more. Mature buds are clavate (club-shaped) to 6 mm long and 3 mm wide, each with a small hemispherical operculum / calyptra. Flowers are white to lemon-yellow and occur mainly in spring and summer.
The fruit of eucalypts are a woody capsule (commonly called ‘gum nuts’) which come in a wide variety of shapes with the top part having a sunken, flat or raised disc and with the valves inserted, disc-level, exserted to strongly exserted. In this species, the capsules are conspicuously conical to pyriform and aid considerably in identification. They are to 9 mm long and 6 mm wide with valves usually enclosed or to rim-level.
This tree has been extensively planted outside its natural habitat due to its reliable broad-domed / symmetrical habit and its hardiness. They do very well in rows and copses. There are many trees to be found in Sydney parks and streets, especially on the edges of football and cricket fields etc. Has likely fallen out of favour in recent times due to councils now (and correctly) prioritising local native species for planting. However, they make a very nice planting in any large landscape, park or garden. Likes a full sun position and can tolerate a variety of soils. Very hardy but can grow to be a large tree, so not suited to small gardens. It some cases, it can invade local bushland reserves, so plant with caution. This Editor has seen it growing as a weed in Lansdowne Bushland Reserve (in the Georges Hall area – Sydney) and at Kamay-Botany Bay National Park, Kurnell.
Editor’s note: A large tree of this species was situated on my parent’s property in Chipping Norton, in a cul-de-sac on the road verge, under which we built a garden. This tree grew to over 25 metres tall by 10 metres wide and gave all the neighbours angst and concern, despite its popularity as shade for car-parking in summer. The tree dropped a lot of leaves, naturally, but never dropped any large branches, not even in severe storms. The tree is likely still there today. On the very near-by Warwick Farm Racecourse, there were some large and grandiose planted specimens of this species with canopies wider than the tree heights, and extending down to arm’s reach. They have now all been removed for development.
They make excellent shade trees in open-grassed areas.
A Koala food tree. This species is one of 27 more common Eucalypt and Corymbia plants eaten by them.
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.
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.
This species regenerates from fire from the lignotuber and epicormic shoots as well as seed.
Eucalyptus is one of three similar genera that are commonly referred to as “eucalypts”, the others being Corymbia and Angophora. It is well-known that Eucalyptus is a large and diverse genus. Between 700 and 950 known species are reported, occurring as far north as The Philippines, as well as Indonesia, New Guinea, Timor and Australia. Only 16 species reportedly occur outside Australia. They occur in all Australian states. NSW currently has about 250 species. (See this website for some detailed information: https://apps.lucidcentral.org/euclid/text/intro/learn.htm).
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).
microcorys – Greek micro (μικρό) – “small” and corys – Ancient Greek for “helmet” which relates to the Corinthian helmet – referring to the small calyptra on the buds.
This species is not considered to be at risk of extinction in the wild.
“Field Guide to Eucalypts Vol 1 South Eastern Australia’ M.I.H.Brooker and D.A.Kleinig. Blooming Books.
NSW Flora Online (PlantNET) – Eucalyptus microcorys profile page
EUCLID – Eucalypts of Australia – Centre for Australian National Biodiversity Research https://apps.lucidcentral.org/euclid/text/entities/eucalyptus_microcorys.htm
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.