Leptospermum continentale

Prickly Teatree

Family: Myrtaceae

An upright dense to sparse shrub that grows to 2 metres tall, usually with a narrow habit.

Its northern extent in NSW is around Gulgong, Merriwa and Mudgee, then extending south through Lithgow, into the Sydney basin and Blue Mountains and Southern Highlands, extending south into the South Coast and Southern Tablelands and Western Slopes, though Victoria and into South Australia.

It is widespread in heath and woodland in well-drained sandy soil as well as swampy areas.

It has smooth bark that is can be shed in stringy strips.

Leaves are narrow-ovate to ovate, to 15 mm long and to 4 mm wide with a sharp point on the end and somewhat concave in cross-section, mid-green.

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 flowers are usually borne singularly on new growth, to 12 mm in diameter, with white or occasionally pink-flushed petals, occurring from Spring to Summer.

The fruit is a capsule to 8 mm wide with 5 valves and remaining on the plant when mature.

In the garden

This species has been in cultivation for a long time (though likely under different names – see notes below). It is sold readily online.

It is reportedly a hardy shrub, tolerating most soils and aspects. Suitable for poorly drained areas and can be used for a hedge or screen. It can be planted in large numbers to form thickets and barriers if desired.

Plant in open sun to part shade. Prune after flowering or fruiting to encourage a denser bush and profuse flowering. Provide some water in dry / very dry times.

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

They are 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 existing.

It has been discovered that this species has been in cultivation for many years, although propagated under a variety of names (eg. L. scoparium and L. juniperinum). The recent revision of the genus has attempted to separate these three species and the following descriptions may help the reader with identification:

  • L. continentale has spreading leaves, 3 mm or less in width and strongly incurved from the margins. The fruit is 7 mm or less in diameter.
  • L. scoparium has spreading leaves more than 3 mm wide and almost flat. The fruit is often 8 mm or more in diameter.
  • L. juniperinum has erect leaves, at least at first, which are 2 mm or less wide and almost flat. Fruits are often less than 7 mm in diameter.

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.

continentale – refers to the interstate distribution of the species on the Australian mainland, in contrast to other species which have more limited distributions.

Not known to be at risk in the wild.

 

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

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

NSW Flora Online (PlantNET) Leptospermum continentale profile page

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

Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers Pty Ltd, Australia.

By Jeff Howes, edited by Dan Clarke