Entelea is a monotypic genus in the mallow family (Malvaceae, order Malvales), containing the single species Entelea arborescens, known by its Māori name whau. It is a shrub or small tree endemic to New Zealand, reaching up to 8 m tall, with large, bright green, obliquely heart-shaped leaves 10–25 cm long that give the plant a lush, tropical appearance. Its white, yellow-centred flowers are around 2 cm across and scented, appearing profusely from early spring to mid-summer, followed by distinctive brown, spiny seed capsules.
The genus is notable for producing one of the lightest woods in the world, rivalling balsa and roughly half the density of cork. This is due to bands of unlignified, pith-like parenchyma that form each year in place of normal growth rings — a feature it shares with its closest relatives, the genera Sparrmannia and Clappertonia, both formerly placed in the family Tiliaceae and now included within Malvaceae.
Both the genus and its type species were formally described in 1824 by the Scottish botanist Robert Brown, based on material collected by Joseph Banks and Daniel Solander during Cook's first voyage in 1769. Whau grows naturally in coastal areas and lowland forest or shrubland across much of the North Island and in scattered South Island localities, with some inland populations thought to trace back to deliberate planting by Māori before European contact. It is a fast-growing but short-lived pioneer species, often among the first plants to recolonise disturbed ground.
Etymology
The common name "whau" is a Māori word likely derived from the Polynesian fau, a name for hibiscus (particularly Hibiscus tiliaceus, which whau superficially resembles). The genus name Entelea means "perfect," referring to its flowers bearing both male and female reproductive organs, while the species epithet arborescens means "becoming a tree."
Distribution
Entelea is endemic to New Zealand, occurring widely across the North Island north of the Māhia Peninsula and Kawhia Harbour, more sparsely further south, and also in the South Island around Golden Bay/Mohua, Nelson, and Manawatāwhi/Three Kings Islands. It has also become naturalised in Ecuador. It typically grows in coastal areas and lowland forest or shrubland, though some inland populations near the Waikato River and Rotorua may derive from historic Māori plantings.
Ecology
Whau is a short-lived pioneer species, with individual trees rarely surviving beyond 15 years, though its seeds remain viable for long periods and can be stimulated to germinate by fire or ground disturbance. On Hen Island (Taranga), it was often the first species to colonise disturbed ground, ahead of other pioneers such as tree nettle and kawakawa, with slower-growing forest-dominant trees like karaka and tawa arriving later.
Cultivation
Whau prefers rich, moist loam and can be grown outdoors in sun or light shade in mild climates, or under glass in colder ones. It is intolerant of drought and can withstand only about 3°C of frost.
Taxonomy Notes
Both the genus Entelea and its sole species were formally described in 1824 by Scottish botanist Robert Brown, from material collected by Joseph Banks and Daniel Solander during Cook's first voyage in 1769. DNA sequence data (ndhF) suggest its closest relatives are the genera Sparrmannia and Clappertonia. GBIF confirms placement in family Malvaceae, order Malvales, and lists the genus as monotypic.
Propagation
Whau is propagated from commercially available seed or readily from hardwood cuttings about 20–30 cm long, with leaves and twigs removed, struck into gritty damp soil and kept moist under a wet sack or newspaper for about a week; new leaves appear after roughly three weeks, and plants are best left several months before transplanting.
