The Australian heaths belong to the plant family Epacridaceae which takes its name from the well known genus Epacris. The family comprises around 34 genera and is distributed mainly in Australia but species are also found in countries to the north of Australia as well as in New Zealand, the Pacific islands and South America. The family is closely related to the Ericaceae, a family widely distributed in the northern Hemisphere and Africa and which includes such well known garden plants as Erica, Rhododendron, Azalea and Pieris.

The Ericaceae is poorly developed in Australia and the Epacridaceae tends to occupy the ecological niche that the Ericaceae occupies in other parts of the world.

Palmate venation on Leucopogon lanceolatus

A general distinction between the two families is the palmate venation of the leaves of most members of the Epacridaceae. "Palmate venation" refers to the way that several main veins radiate from the base of the leaf. Because of the small leaves in many species of the Epacridaceae, the veins often appear to be parallel.

Recent research suggests that the Epacridaceae may be more closely related to the Ericaceae than previously thought and may be relegated to sub-family status within the Ericaceae in the future.

Present thinking, however, divides the Epacridaceae into 7 Tribes:

• Tribe Archeriaea - Comprises the single genus Archeria, which occurs in Tasmania and New Zealand.
• Tribe Cosmelieae - Three genera, the best known being Sprengelia.
• Tribe Epacrideae - Five genera including Epacris and Woollsia.
• Tribe Oligarrheneae - Comprises the two genera Needhamiella and Oligarrhena from Western Australia.
• Tribe Prionoteae - Two genera including Prionotes.
• Tribe Richeae - Three genera including Richea and Dracophyllum.
• Tribe Styphelieae - This is the largest Tribe. It includes Astroloma, Leucopogon, Lissanthe and Styphelia.

A number of species are attractive plants for cultivation due to their prolific and colourful flowers. The genus Epacris is the most commonly cultivated member of the family and one member of the genus, Epacris impressa (common or pink heath) is the floral emblem of Victoria. Apart from Epacris, other members of the family are not often seen in general cultivation but genera grown by enthusiasts include Astroloma, Dracophyllum, Leucopogon, Prionotes, Richea, Sprengelia, Styphelia and Woollsia.

Several members of the family were introduced into cultivation in Europe within a few years of British exploration of the east coast of Australia in the late 1700s - early 1800s. Species grown in Europe included species of Astroloma, Brachyloma, Epacris, Leucopogon, Lissanthe, Melichrus, Monotoca, Styphelia and Woollsia.

Characteristics

For the most part, the Australian heaths are small shrubs but a few species occur as small trees. They can be found in a range of habitats and are a common component of low, exposed vegetation known as heathland. Often they will be found in areas of constant moisture but also occur in temperate open forest and woodland, sub-alpine areas and the coastal zone. They tend to be absent in the arid zone and are rare in rainforests.

The leaves are usually alternate or spirally arranged and sometimes sheathing around the stems. They are often stiff and can have a sharply pointed tip. The veins are generally narrowly palmate.

Small, fleshy fruit Leucopogon lanceolatus

The flowers are usually tubular or cup-shaped with four or five spreading lobes and occur in spikes or racemes or occasionally solitary. The flowers usually have as many stamens as there are corolla lobes but there are some species in which male and female flowers occur on separate plants (dioecious) and in such cases, female flowers have only rudimentary stamens. Flowers are generally small but there are exceptions (eg. Prionotes and some Epacris).

The fruit is either a capsule which splits when ripe to release the seed or a drupe (a fleshy fruit with its seed enclosed in a hard stone).