''Melaleuca decussata'', commonly known as cross-leaf honey-myrtle or totem poles, is a plant in the myrtle

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Myrtaceae Myrtaceae, the myrtle family, is a family of dicotyledonous plants placed within the order Myrtales. Myrtle, pōhutukawa, bay rum tree, clove, guava, acca (feijoa), allspice, and eucalyptus are some notable members of this group. All speci ...

native to

South Australia South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...

and both native and naturalised in Victoria. It is an adaptable shrub, grown in many parts of

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

for its attractive foliage but is regarded as an environmental weed in parts of Victoria.

Description

''Melaleuca decussata'' is a densely branched shrub growing to a height and width of . The leaves are arranged in alternating pairs at right angles to the ones above and below so that the leaves are in 4 rows along the stems (

decussate Decussation is used in biological contexts to describe a crossing (due to the shape of the Roman numeral for ten, an uppercase 'X' (), ). In Latin anatomical terms, the form is used, e.g. . Similarly, the anatomical term chiasma is named aft ...

). The leaves are long, wide, linear, narrow elliptic or narrow egg-shaped tapering to a point and concave in cross section. They also have prominent oil glands on their lower surface. The flowers are a shade of pink or purple but fade rapidly to white. They are arranged in spikes on the ends of branches which continue to grow after flowering and on the sides of the branches. The spikes are up to in diameter, long and have between 6 and 22 individual flowers. The petals are long and fall off as the flower ages. The stamens are arranged in five bundles around the flowers with 12 to 26 stamens in each bundle. The flowering season is from August to May but flowers mostly appear from November to February in the species' native range. The fruit which follow are woody capsules, characteristically fused together at their bases and sunken in the stem.

Taxonomy and naming

''Melaleuca decussata'' was first formally described by Robert Brown in 1812 in the second edition of ''

Hortus Kewensis ''Hortus Kewensis, or a Catalogue of the Plants Cultivated in the Royal Botanic Garden at Kew'' by William Aiton was a 1789 catalogue of all the plant species then in cultivation at the Royal Botanic Gardens, Kew Royal Botanic Gardens, Kew is ...

'' from material collected from the southern coastal region of Australia. 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 ...

(''decussata'') refers to the decussate arrangement of the leaves.

Distribution and habitat

''Melaleuca decussata'' occurs between coastal areas of South Australia (including the

Eyre Peninsula The Eyre Peninsula is a triangular peninsula in South Australia. It is bounded by the Spencer Gulf on the east, the Great Australian Bight on the west, and the Gawler Ranges to the north. Originally called Eyre’s Peninsula, it was named aft ...

) and the centre of eastern Victoria. Melaleuca decussata 2

Conservation status

This species has been declared an environmental weed in the

Geelong Geelong ( ) (Wathawurrung: ''Djilang''/''Djalang'') is a port city in the southeastern Australian state of Victoria, located at the eastern end of Corio Bay (the smaller western portion of Port Phillip Bay) and the left bank of Barwon River, ...

area, the catchments of the Broken and Goulburn rivers and in the

Wimmera The Wimmera is a region of the Australian state of Victoria. The district is located within parts of the Loddon Mallee and the Grampians regions; and covers the dryland farming area south of the range of Mallee scrub, east of the South Austral ...

bioregion. It is a garden escape which becomes naturalised in grasslands and grassy woodland. It is believed to be a threat to several natural vegetation associations and forms dense stands in native pastures. It grows in low nutrient soils subject to inundation.

Use in horticulture

''Melaleuca decussata'' is a hardy garden plant with attractive foliage. It will grow in most situations and has attractive mauve-coloured flowers, although they fade quickly to white. It is not advisable to plant this species within of a wastewater pipe because of its potential to cause damage.

References

{{Taxonbar, from=Q6811004 Flora of South Australia Flora of Victoria (Australia) decussata Myrtales of Australia Plants described in 1812