''Leucopogon exolasius'', commonly known as Woronora beard-heath, is a species of flowering plant in the heath family

Ericaceae The Ericaceae are a family of flowering plants, commonly known as the heath or heather family, found most commonly in acidic and infertile growing conditions. The family is large, with c.4250 known species spread across 124 genera, making it th ...

and is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to a small area of New South Wales. It is an erect shrub with oblong or elliptic leaves, and drooping, white, tube-shaped flowers.

Description

''Leucopogon exolasius'' is an erect shrub that typically grows to a height of and has softly-hairy branchlets. Its leaves are oblong to elliptic, long and wide on a petiole long. The edges of the leaves are turned down or rolled under, the upper surface convex and the lower surface striated. The flowers are arranged singly or in groups of up to three in leaf axils on peduncles long, and are pendent, with

bracteoles In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

long at the base. The

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

s are long, the petals white and joined at the base to form a tube long. the petal tube is covered with tiny hairs on the outside, the lobes long and shaggy-hairy on the inside.

Taxonomy

Woronora beard-heath was first formally described in 1867 by

Ferdinand von Mueller Baron Sir Ferdinand Jacob Heinrich von Mueller, (german: Müller; 30 June 1825 – 10 October 1896) was a German-Australian physician, geographer, and most notably, a botanist. He was appointed government botanist for the then colony of Vict ...

who gave it the name ''Styphelia exolasia'' in his '' Fragmenta Phytographiae Australiae'' from specimens collected by

Ludwig Leichhardt Friedrich Wilhelm Ludwig Leichhardt (), known as Ludwig Leichhardt, (23 October 1813 – c. 1848) was a German explorer and naturalist, most famous for his exploration of northern and central Australia.Ken Eastwood,'Cold case: Leichhardt's dis ...

near the village of Camden. In 1868,

George Bentham George Bentham (22 September 1800 – 10 September 1884) was an English botanist, described by the weed botanist Duane Isely as "the premier systematic botanist of the nineteenth century". Born into a distinguished family, he initially studi ...

changed the name to ''Leucopogon exolasius'' in ''

Flora Australiensis ''Flora Australiensis: a description of the plants of the Australian Territory'', more commonly referred to as ''Flora Australiensis'', and also known by its standard abbreviation ''Fl. Austral.'', is a seven-volume flora of Australia published be ...

''. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

(''exolasius'') means "hairy on the outside", referring to the floral tube.

Distribution and habitat

''Leucopogon exolasius'' is only known from a few locations in the

Sydney Sydney ( ) is the capital city of the state of New South Wales, and the most populous city in both Australia and Oceania. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about towards the Blue Mountain ...

region and on the Central Coast of New South Wales, including along the

Georges River The Georges River, also known as Tucoerah River, is an intermediate tide-dominated drowned valley estuary, located to the south and west of Sydney, New South Wales, Australia. The river travels for approximately in a north and then easterly ...

, in

Heathcote National Park Heathcote National Park is a protected national park that is located in the southern region of Sydney, New South Wales in eastern Australia, and is situated on Dharawal country. The national park is situated approximately southwest of the Sydn ...

and along the

Grose River The Grose River, a perennial river that is part of the Hawkesbury-Nepean catchment, is located in the Blue Mountains region of New South Wales, Australia. Course and features The Grose River rises from north east of Mount Victoria within the ...

. It grows in woodland, often on sandstone hillsides along creek banks.

Conservation status

''Leucopogon exolasius'' is listed as "vulnerable" under the Australian Government ''

Environment Protection and Biodiversity Conservation Act 1999 The ''Environment Protection and Biodiversity Conservation Act 1999'' (Cth) is an Act of the Parliament of Australia that provides a framework for protection of the Australian environment, including its biodiversity and its natural and cultu ...

'' and the New South Wales Government '' Biodiversity Conservation Act 2016''. The threats to the species include its small population size, habitat loss, weed invasion and inappropriate fire regimes.

References

{{Taxonbar, from=Q27828577 exolasius Ericales of Australia Flora of New South Wales Plants described in 1867 Taxa named by Ferdinand von Mueller