Melaleuca cardiophylla is known as the Umbrella Bush and is a small to medium, erect to spreading shrub, potentially reahcing 4 metres tall and spreading just as widely or more.
It tends to have intertwined branches.
It is endemic to the western parts of Western Australia, growing very close to the coast, from Perth to Exmouth, with some inland records east of Coral Bay (Barlee Range Nature Reserve).
It forms part of coastal shrubland and heathland, usually on sandy soils but also limestone-based soils.
Melaleuca spp. can present with simple and alternate or opposite leaves. In this species, leaves are alternate to spiral, somewhat clustered, stem-clasping and heart shaped (cordate) (hence the species name), to about 9 mm long and 7 mm wide, mid to dark green in colour.
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, white flowers are carried in small clusters of up to 5, with clusters extending along the branches in spikes of up to 5 cm or more. This flower arrangement is similar in appearance to those of the better known M. thymifolia. The flowering period is variable but occurs between October and February. The specimen illustrated flowered in mid-January.
The fruit is a capsule. In this species, it is comparatively large, to 10 mm in diameter and woody.
M. cardiophylla could be cultivated in shrubberies and informal hedges. Pruning after flowering is recommended to keep plants from becoming straggly.
The specimen in our cold climate garden (near Armidale, NSW) is about ten years old. The Umbrella Bush has proved to be very hardy and free-flowering.
A nice plant to grow, reportedly needs very good drainage to do well in the eastern states, in a full sun position. Prefers low humidity. Give some room to spread out. Can create a very dense bush for bird habitat.
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.
cardiophylla – from Greek – cardia (καρδία) – meaning “heart” or “of the heart” and –phylla (φύλλα) meaning “leaves” – capturing the heart-shaped leaves of the species.
This species is not considered to be at risk of extinction in the wild.
Western Australian Herbarium (1998–). Florabase: The Western Australian Flora – Melaleuca cardiophylla profile page https://florabase.dbca.wa.gov.au/browse/profile/5887
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.
Cambridge Coastcare – Plants of the West Coast – Melaleuca cardiophylla profile page https://cambridgecoastcare.com.au/wp-content/uploads/2015/05/P89_Melaleuca-cardiophylla-TANGLING-MELALEUCA.pdf