Leptospermum deanei

Family: Myrtaceae

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.

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).

Leptospermum 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 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.

In the garden

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 Leptospermum species make good garden plants.

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.

Propagation

Leptospermum species are generally easy to propagate from seed or cuttings.

Other information

Most Leptospermum species are endemic to Australia where most are found in southern areas of the country and many make desirable garden plants. Current estimates recognize about ninety species of Leptospermum along with many cultivars now existing.

The nectar from the flowers of one species (L. scoparium) is harvested by bees, yielding honey, which is marketed as Manuka honey.

Many Leptospermum 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.

Leptospermum – derived from the Greek words leptos meaning “fine” or “slender” and sperma which means “seed” referring to the thin brown seeds of 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.

Australian National Botanic Gardens – Leptospermum profile page https://www.anbg.gov.au/leptospermum/

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)                                                          https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Leptospermum~deanei

By Jeff Howes, edited by Dan Clarke