Brachychiton discolor

Brachychiton discolor, also known as the two-coloured bottle tree, white kurrajong or Sterculie, is a medium-sized Australian tree with relatively low hardiness, featuring a spectacular pink summer flowering. Particularly well adapted to the dry summers of the Mediterranean coast and its mild winters, it can be grown in large containers elsewhere, so that it can be sheltered indoors during winter. Over time, it develops into a small tree with a variable habit, conical, rounded or more spreading. The trunk thickens, becoming massive with age, classifying this plant in the category of bottle trees. Its foliage is highly decorative, but it is its superb pink flowering in summer that catches all the attention. A rare tree that deserves to be more widely planted in the most favored coastal gardens.

Brachychiton is a genus of trees that includes 31 species, all native to Australia and Papua New Guinea. Formerly classified as Sterculiaceae, it now belongs to the large family of Malvaceae, like Hibiscus, Lime or Baobab. Trees with a very ancient history, present on Earth for 50 million years, they are monoecious, meaning they bear separate male and female flowers.
Brachychiton discolor is a tree native to eastern Australia, growing in the dry tropical forests of Queensland and New South Wales. In these regions, it grows into large specimens of 20 to 30m (65ft 7in to 98ft 5in) in height, with a single trunk or sometimes multiple trunks. Its leaves persist in winter, but fall during the dry season, which is an adaptation to the arid climate. Just like its swollen trunk that allows it to store water.

In France, it is occasionally found on the French Riviera, for example at Parc Saint-Bernard in Hyères, where the necessary conditions for its development are met, namely dry and hot summers, and mild winters without excessive rainfall. Its development is much more modest than in Australia: it sometimes reaches 10m (32ft 10in) in height, but more commonly 6 or 7m (19ft 8in or 23ft). This bottle tree can tolerate temperatures as low as -5° to -7°C under good conditions (dry and non-humid cold, sheltered from the wind, dry soil...).

The alternate leaves measuring 10 to 15cm (3.9 to 5.9in) are palmate, showing 5 or 7 lobes. Green on the upper surface, they are somewhat greyish on the lower surface due to the presence of numerous short hairs. They briefly fall in summer before the appearance of the flowering, which is the main asset of this Brachychiton. It takes the form of pendulous clusters, composed of 3 to 10 pink flowers, either female or male, as the plant is monoecious (flowers of both sexes coexist on the same plant). Bell-shaped, measuring 5cm (2in) in diameter, with 5 slightly curved lobes at the tip, they are dark pink on the outer side and lighter pink on the inner side. Highly visible on the bare branches, they provide a magnificent spectacle for several weeks. The female flowers then produce brown maroon fruits, 15cm (5.9in) long, resembling cocoa pods. They contain 30 to 50 orange seeds, which are edible once roasted. Beware, they are protected by irritating hairs, so gloves should be worn when handling the fruits.
The greenish trunk for years gradually turns grey as its diameter increases, and can even become slightly swollen at the base. It contributes fully to the exotic appearance of this species.

This Brachychiton discolor is a low-maintenance plant, perfectly adapted to the climate of the French Riviera. It can be integrated into a diverse bed of other exotic plants, especially bushes in the foreground, as it tends to branch relatively high. Plant a Viburnum lucidum at its base, a evergreen Viburnum with beautiful shiny dark green foliage, which curiously turns red-purple in autumn. Its fragrant white flowering precedes that of the Brachychiton in spring. Another evergreen shrub well adapted to dry conditions, Fremontodendron californicum will dazzle you with its bright yellow flowering in June-July. And for spring flowers, nothing beats a few various Cistus plants, which will enchant you with their fugacious but constantly renewed flowers in shades of pink, white or purple depending on the species.