Breynia cernua

fart bush


Breynia cernua

(Poir.) Müll.Arg. 1866

pronounced: BRAY-nee-uh KER-new-uh

(Phyllanthaceae — the phyllanthus family)

synonym — Breynia stipitata

Müll.Arg. 1866

pronounced: BRAY--nee-uh stip-ee-TAH-tuh

common name: fart bush

native 4Breynia was named in honour of Johann Philipp Breyn (1637 – 1716), German botanist and botanical author; cernua is from the Latin cernuus, inclining the head, stooping; stipitata is also Latin, stipes (stipitis), a stalk. There is some confusion over the taxonomy of this plant, with recent research suggesting that Breynia stipitata may be a separate species: Kew shows them as separate.

The Fart Bush is fairly common in monsoon forest, but can turn up in moist areas anywhere, especially in beach forest and vine thickets. In the rainforest it is a regrowth species favoured by disturbance. It is found right across the top end of Australia, and down the eastern coastal strip as far as central Queensland, in an altitudinal range from near sea level to about 800 m. It also occurs in Malesia.

It usually flowers and fruits as a shrub between one and two metres tall, with a weeping appearance. The broadly lanceolate leaves are arranged distichously on twigs (alternately on two vertical rows on opposite sides) so that each twig represents a compound leaf. Often the stems have a zigzag appearance. The stipules are broadly triangular, small but persistent, 1 – 2 mm in length. The leaf blades are about 2.5 – 4 cm by 1.5 – 2 cm in size, the lateral veins forming fairly distinct loops inside the margin. The leaves emit a foul odour when crushed (hence the common name), from the methyl mercaptan they contain. This is a colourless inflammable gas that is easily ignited; when heated to decomposition it emits highly toxic fumes. dangerous 2The gas is highly irritant when it contacts moist tissues such as the eyes, skin, and upper respiratory tract. It can also induce headaches, dizziness, nausea, and, in extreme cases, coma and death.

The plant is monoecious, with tiny greenish flowers. The male flowers have sessile anthers, fused to one another to form a staminal column in the centre of the flower; the female flowers have a perianth that resembles an egg cup, with the pistil enclosed like an egg in the egg cup; the style is fleshy.

The tepals are persistent at the base of the fruit, which is a globular to depressed globular red berry up to about 1 cm in diameter, on a pedicel about 3 – 5 mm long. The seeds are about 4 – 5 mm long.

This is a food plant for the larval stages of the Common Grass Yellow butterfly, Eurema hecabe, and the moth Dysgonia infractafinis.


Photographs taken in Horseshoe Bay 2014
Page last updated 23rd October 2018