Melaleuca quadrifaria, Limestone Honey-myrtle, is a tall shrub that may reach a height of 5 to 6 metres, spreading to several metres wide and forming a dense bush.
It is another melaleuca endemic to the south of Western Australia as well as the west of South Australia, growing along the south coast and to several hundreds of kilometres inland, from as far west as Newdegate, north-east to Lake Cowan (and a bit further on) and east to as far as the border of Western Australia and South Australia.
It reportedly grows on clay soils including sandy clays over limestone, on lake flats as part of shrublands, heathlands and mallee-shrublands.
Melaleuca spp. can present with simple and alternate or opposite leaves. In this species, leaves are opposite and decussate (where each pair of leaves is orientated at right angles to the immediate-adjacent pairs), linear in shape and distinctively curve upwards, to 7 mm long by 1.5 mm wide
In Melaleuca species, flowers are usually arranged in spikes or heads. Within the head or spike, the flowers are often in groups of two or three. Flowers have five sepals (sometimes fused into a ring of tissue) and five petals which are typically small and do not persist on the flower for long.
Like many other Myrtaceae genera, the flowers are conspicuously staminate with each flower having many stamens surrounding one carpel. The stamens are typically fused into five separate bundles (staminal claws) which each bundle sitting opposite a petal (a generally useful identifying feature for the genus to distinguish it from Callistemon). Melaleuca flowers do not have pedicels (sessile).
In this species, creamy-white flowers are borne in terminal or lateral clusters or heads, with clusters about 20 mm in diameter, and consisting of up to 30 flowers in groups of 3s; each flower about 10 mm long; appearring in spring and summer.
The fruits are capsules, which are roughly round with a pentagon-shaped opening, to about 3 mm wide.
Melaleuca quadrifaria could be cultivated in hedges and screens. The dense foliage provides safe nesting sites for small native birds.
It is known to be successfully cultivated in coastal environments and can tolerate salt winds.
They attract a wide range of native insects. Remove the spent flowers to improve foliage density and flowering.
Plant in full sun on a well-draining soil.
Propagate from seed and cuttings.
This species can regenerate well after fire through epicormic shoots and basal coppicing as well as form the seed bank.
The genus Melelauca has been subject to recent taxonomic revision with early and recent botanists including Ferdinand von Mueller and Lyndley Craven (deceased in 2014) proposing to expand the genus to include all Callistemon spp. and others. Craven et al. (2014) published new species combinations which included the renaming of all Callistemon species to Melaleuca, based on evolutionary relationships and DNA evidence and other features.
Currently, the NSW Herbarium advises that the Callistemon genus can still be used.
Melaleuca is a genus of about 220 species, occurring mostly in Australia, but also Malesia and New Guinea. Australia has about 215 species with 210 reported endemic, occurring in all states. NSW currently has 30 species.
Melaleuca – is derived from the Ancient Greek mélas (μέλας) meaning “dark” or “black” and leukós (λευκός) meaning “white”, apparently because one of the first specimens described had fire-blackened white bark.
quadrifaria – Latin: quadri meaning “four” and fidus meaning “split”. This refers to the decussate arrangement of the leaves – appearing to be in four rows.
This species is not considered to be at risk of extinction in the wild.
Western Australian Herbarium. Florabase: The Western Australian Flora. Melaleuca quadrifaria profile page https://florabase.dbca.wa.gov.au/browse/profile/5957
Wikipedia – Melaleuca quadrifaria profile page https://en.wikipedia.org/wiki/Melaleuca_quadrifaria
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.