Jagera pseudorhus var. pseudorhus

foambark tree


Jagera pseudorhus var. pseudorhus

Radlk. 1879

pronounced: JAY-ger-uh sue-DOH-russ

(Sapindaceae — the lychee family)


common name: foambark tree

native 4Jagera is named for Dr. Herbert de Jager who worked for the botanist Rumphius, collecting plants in Indonesia in the 19th century; pseudorhus is from the Greek ψευδο (pseudo), false, and 'ρους (rhus), the Sumac tree.

This is a rainforest tree of eastern Australia. Its common name is due to the saponin foam that forms on the bark after heavy rain, or if pieces of the bark are shaken up in water. It is found from the Bloomfield River (15ºS) in far North Queensland south to the Manning River (35ºS) in NSW. Its altitudinal range is from near sea level to 850 m. It grows in drier, more seasonal rainforest and beach forest. It also occurs in New Guinea.
On Magnetic Island, there are examples of this tree on the Hawkings Point walking track, at Arthur Bay, and by the walking track at the end of Mandalay Avenue in Nelly Bay.

The tree is usually a small one, but can grow up to 30 m tall, and 50 cm in trunk diameter. It develops a crown at maturity. The bark is smooth and grey, with horizontal raised ridges. Raised horizontal leaf scars are often visible on the stem. The bases of larger trees are often flanged.

The leaves are alternate and pinnate, with 8 – 26 leaflets, each 4 – 6 cm long, with very short stems. They are toothed, unequal-sided, particularly at the base, and have a pointed tip. The young shoots and the young twigs are hairy and longitudinally grooved. The midrib is hairy and raised on the upper surface of the leaflet blades.

Yellow-brown flowers form on much-branched terminal panicles, 4–16 cm long, from April to May. The petals are about 2 mm long. There are usually 8 stamens, the filaments hairy. The disk is continuous, surrounding the ovary and the base of the staminal filaments.

dangerous 2The fruit forms in August to November, an egg-shaped capsule with 3 cells, about 18 mm long, and hairy inside and out; the capsules mature to a brown colour, after first being a violet pink. There is one seed per cell, with a small basal aril; the dark brown or black seeds are about 7–8 mm long by 4–5 mm broad. Care needs to be taken while handling the capsule, as the hairs can cause skin irritation. The fruit is eaten by the Australian King Parrot and the Green Catbird. Germination from fresh seed is not generally difficult.

The beautiful form of this tree makes it well-suited as an ornamental. If planted in a garden, it should be surrounded by other plants, to discourage people from picking up any fallen fruits. Indigenous Australians used the froth from crushed bark both as a soap and as a fish poison. The bark was also used during World War I as a foaming agent for beer. There is another recognized variety of this species, var. integerrima, restricted to the Atherton Tableland and surrounding mountains, at an altitudinal range from 650 – 1200 m. This variety grows in well-developed upland and mountain rain forest. Both varieties are useful honey trees, and the timber makes good tool handles.


Photographs taken at Nelly Bay, 2012-2015
Page last updated 22nd January 2019