Eucalyptus caesia is commonly known as Gungurru. It is a small tree that may reach a height of 9 metres if a single trunk develops. As a mallee, with multiple trunks, then the height may be restricted to 6 metres.
It is endemic to Western Australia, growing in a region which radiates eastwards from Perth, to as far north-east as Walyahmoning Nature Reserve and as far south-east as around Hyden.
It forms part of dry sclerophyll shrubby woodlands and mallee woodlands / shrublands on grnite outcrops.
Gungurru has a slender growth habit with pendulous branches and an open crown. The bark is initially smooth red-brown and when shed exposes the new bark that is greenish or yellow-brown.
Eucalyptus spp. have simple and usually alternate adult leaves with juvenile leaves starting off opposite to alternate (disjunct). In this species, the juvenile leaves are opposite early and then alternate, cordate to 8 cm long and 6 cm wide, thick in texture and green to blue-green with deep red stems. Adults leaves are narrow-lanceolate, leathery, up to 12 centimetres long and grey-green. Stems have a frosted appearance (covered in waxy resin).
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 large, stunning flowers are about 3 centimetres across, red in colour with stamens having yellow anthers; carried in umbellasters of three. Buds are very attractive with a red-green colour, to 3 cm wide and almost diamond-shaped in apperance. Flowering occurs between June and September and at this time attracts honeyeaters.
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, fruits are comparitively large, to 2.5 cm by 2.5 cm, cup-shaped to urceolate, on long pedicels (about 3 cm).
Our tree has a single trunk and is close to nine metres tall, in a cold-climate garden near Armidale.
Give a well-drained soil and do not over water. Give a sunny spot; it is very drought tolerant.
In our harsh climate, Gungurru could be damaged by frost. Our plant has survived and thrived because it is sheltered in one of our dense, diverse shrubberies. Our plant (see image) flowered for the first time in July 2013. Blooms are followed by urn-shaped gum nuts that are 3 centimetres long by 2.5 centimetres wide. Both flowers and fruits are so heavy that they weigh down the branches. This accentuates the pendulous growth habit.
There is also a naturally occurring form, also rare, that has larger flowers and fruits with pendulous branches may reach the ground. This form is known as ‘Silver Princess’ and is widely cultivated. Our plant appears to be the usual form.
Regardless of which form you grow this is a spectacular eucalypt with attractive trunk, stems, flowers and fruits. It is highly desired due to its very showy flowers.
It can be subject to dieback after a few years.
Propagate from seed.
This species can regenerate from the lignotuber and epicormic shoots after fire. May also regenerate from seed.
As mentioned above, there is a weeping form sold as a popular cultivar called ‘Silver Princess’.
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).
caesia – Latin – caesius meaning bluey-grey or glaucous – referring to the waxy bloom on the stems, buds and fruits.
This species is not considered to be at risk of extinction in the wild. However, they are considered rare and are under monitoring.
Botanic Gardens and Parks Authority – Government of Western Australia – Eucalyptus caesia profile page https://www.bgpa.wa.gov.au/about-us/information/our-plants/plants-in-focus/650-eucalyptus-caesia
Florabase – Western Australian Herbarium – Eucalyptus caesia profile page https://florabase.dpaw.wa.gov.au/browse/profile/5575
Gardening with Angus – Eucalyptus caesia ‘Silver Princess’ profile page https://www.gardeningwithangus.com.au/eucalyptus-caesia-silver-princess/
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.