A very rare shrub, growing to 5 metres tall.
It is restricted to Sydney, growing in the Hornsby, Warringah, Ku-ring-gai and Ryde Local Government Areas.
It is found in dry sclerophyll forest and woodland, typically growing on lower hill slopes or near creeks, on Hawkesbury Sandstone and associated sandy loams.
It is listed as threatened with extinction in the wild.
The bark is grey and can be seen to peel in long strips; with the new growth densely hairy.
Gaudium spp. have simple and alternate leaves. In this species, leaves are narrow-elliptical to oblanceolate, to 15 mm long and to 2 mm wide with a soft, blunt tip which are sometimes turned downwards. The leaves have no obvious petioles (sessile).
Gaudium spp. typically produce solitary flowers, or in small groups of 2s and 3s or more, within the leaf axils. Flowers have 5 petals and sepals and have a symmetrical rotate shape. Stamens are produced in groups of 5 which surround 1 carpel (female part). The prominent feature in Gaudium/Leptospermum is the hypanthium, a cup or vase-shaped receptacle that supports the flower.
In this species, the flowers are borne singly on short side shoots, white in colour, occasionally with some pink, to 10 mm in diameter. The hypanthium is mostly glabrous. Flowering occurs from October to November.
The fruit is a capsule, about 4 mm in diameter, and falling from the plant once ripe.
A species not known to be cultivated, likely due to its threatened species status. It may become available for cultivation in the future. It is found naturally on sandstone-sandy soils, in dappled light, and so may need these conditions to grow well.
Most Gaudium species make good garden plants.
Gaudium (formerly Leptospermum) are generally susceptible to the webbing caterpillar. Usually, the most effective control method for this pest is removing infestations by hand or, if necessary, you can systematically spray with a suitable pesticide. They are also prone to scale insects which is best treated by spraying white oil solution.
Gaudium (formerly Leptospermum) species are generally easy to propagate from seed or cuttings.
Please note the following changes:
In 2023, the genus Leptospermum of about 90-100 species, was reclassified and reduced to about 34 species, occurring in south-east Asia, New Guinea, Australia and New Zealand. Australia now has at least 31 species, occurring mostly in the eastern states. NSW currently has 31 species. The remaining approximately 60 species, that were previously Leptospermum, are now classified in four new genera: Aggreflorum, Gaudium, Leptospermopsis and Apectospermum. Species in these new genera are titled as such on this website with the synonymous Leptospermum name also indicated, for clarity.
Gaudium is a genus of 22 species, endemic to Australia, occurring mainly in eastern Australia, with one species occurring in Western Australia. NSW currently has 15 species. Gaudium differs from Leptospermum by having fruiting-capsules usually deciduous and either non-woody, or with non-woody valves. In addition, the seeds of Gaudium are ovoid to cuneiform and with a reticulate (net-like) surface, whereas they are linear with longitudinal striations in Leptospermum.
Many Gaudium species have an ability to regenerate vegetatively after fire with suckering basal growth and branch-shoots. They will also regenerate by seed.
The general common name, Teatree, derives from the practice of early Australian settlers who soaked the leaves of several species in boiling water to make a herbal tea.
Gaudium – Latin for ‘joy’ – in tribute to NSW Herbarium Botanist Joy Thompson (1923-2018) who published an extensive study on Leptospermum in 1989 (which recognised several new species), and was considered the primary expert on the genus.
deanei – named after Henry Deane (1847-1924). Specimens of this species were collected in 1883 by the railway engineer at Devlins Creek in the Lane Cove River valley and were probably collected by Deane when he was working on the nearby railway line. These specimens lay undescribed for over 100 years in the National Herbarium of New South Wales query box. The specific epithet honours Henry Deane, whose major project was electrifying the Sydney tramway system
This species is listed as threatened with extinction in the wild at both the State and Commonwealth level with the category of Vulnerable.
NSW Flora Online (PlantNET) – Gaudium profile page https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=gn&name=Gaudium
NSW Office of Enviroment and Heritage – Threatened species profile page – Leptospermum deanei https://www.environment.nsw.gov.au/threatenedspeciesapp/profile.aspx?id=10468
Wikipedia Page – Henry Deane https://en.wikipedia.org/wiki/Henry_Deane_(engineer)
NSW Flora Online (PlantNET) – Gaudium deanei profile page https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Gaudium~deanei