Buckinghamia celsissima F.Muell.

Overall Size and Growth Habit

Buckinghamia celsissima is a large tree that reaches up to 30 m (98 ft) tall in its native rainforest habitat, and grows much smaller when cultivated.

Leaf Surface and Petiole

Its leaves are dark green on the upper surface and somewhat glaucous or whitish on the lower surface, attached to petioles 10–20 mm (0.4–0.8 in) long.

Leaf Shape Variation by Shoot Age

The first few leaves on a new shoot may be deeply lobed, while leaves on older twigs are simple with entire margins.

Mature Leaf Dimensions

Mature leaves are elliptic, growing up to around 20 cm (7.9 in) long and 7 cm (2.8 in) wide.

Flowering Period and Inflorescence

Showy cream-coloured flowers bloom through summer and autumn, borne on axillary or terminal pendant raceme inflorescences up to 27 cm (11 in) long.

Individual Flower Structure

Individual flowers cluster densely along the inflorescence axis, growing on pedicels about 8 mm (0.3 in) long, with tepals 7–10 mm (0.3–0.4 in) long.

Fruit Type and Common Name

Fruits of this species, commonly called the ivory curl tree, are follicles.

Fruit Colour Changes During Development

They are green while developing, and turn brown or black when mature.

Mature Fruit and Seed Characteristics

Mature fruits reach up to 30 mm (1.2 in) long by 20 mm (0.8 in) wide, and hold up to 6 small brown seeds that are released when the fruit splits open.

Natural Geographic Range and Altitude

In the wild, Buckinghamia celsissima occurs naturally in northeastern Queensland, Australia, from near Rossville to the Paluma Range north of Townsville, growing at altitudes between 200 m (660 ft) and 1,000 m (3,280 ft).

Wild Habitat and Substrate

It grows in well-developed rainforest on deep red volcanic soils, and also occurs in drier rainforest types associated with kauri pine.

Butterfly Host Role

Ecologically, the ivory curl tree is a host species for larvae of the cornelian butterfly.

Flower-Associated Fauna

When flowering, its inflorescences attract a wide variety of insects, including the beetle Dilochrosis brownii, which in turn attracts insectivorous birds.

Seed Predators

Its seeds are eaten by crimson rosellas (Platycercus elegans).

Cultivation Popularity

The ivory curl tree is now a widely popular planted tree for parks, streets, and private gardens in regions far outside its natural native range.

Cultivation Advantages

Its popularity stems from its ease of cultivation, abundant mass flowering, and varied foliage shape and colour.

Cultivated Size in Southern Regions

It grows well as far south as Sydney and Melbourne, but only reaches 7–8 m (23–26 ft) tall in these regions.