Sigesbeckia orientalis

St. Paul's-wort


Sigesbeckia orientalis

L. 1753

pronounced: seegs-BECK-ee-uh or-ee-en-TAH-liss

(Asteraceae — the daisy family)


common names: St. Paul's-wort, stickyweed, xi xian cao

Sigesbeckia is for Johann Georg Siegesbeck (1686 – 1755), a Prussian physician and botanist, Director of the St. Petersburg Botanic Gardens and one-time friend of Linnaeus. He disapproved, on moral grounds, of Linnaeus’s ideas about plants having male and female sexual organs for their reproduction. He mockingly asked whether God would allow 20 men or more (the stamens) to have one wife in common (the pistil), and referred to Linnaeus’s system as “loathsome harlotry”. Linnaeus retaliated by naming this rather unpleasant little plant after him. Orientalis is Latin for ‘of the east’. The plant’s Chinese name means ‘pig pungent weed’, which is self-explanatory.

There is debate about whether the plant, Asian in origin, is also native to Australia, or introduced here.

The plant grows in soils ranging from shallow stony to the grey soils of river banks, on the edges of woods, and by streams and marshes. The plants photographed were growing on the edge of a swampy region near the West Point road. This plant, that seems to be fairly rare on Magnetic Island, is an annual erect herb that grows to about 80 cm, the stems slightly pubescent, and brownish green in colour. The leaves are lanceolate to hastate, 2 – 15 cm long by 1 – 7 cm wide, opposite in remote pairs, petiolate, with serrate margins, pubescent with glandular hairs and prominent veins. The whole plant is very sticky, and adheres to anything that touches it or brushes by. The leaves exude a sap-like secretion.

The capitulum is up to about 1 cm in diameter. The outer involucral bracts are irregular, spreading, narrow-spatulate, up to about 1 cm long, densely covered with dark stalked glands, There are about 8 ray florets, and 10 – 15 yellow disk florets. The achenes are 2 – 3 mm long, slightly angled, and black.

The secretion from the leaves contains a crystalline compound similar to aspirin. The plant is much used in Chinese traditional medicine to clear heat and release toxins. It is also considered to calm the spirit and pacify the liver, which is reckoned to be the seat of all emotions, and so it is used to treat irritability and insomnia, as well as a general anti-inflammatory and to remedy rheumatic pains. It is used externally to aid in the healing of wounds and burns, and it is also reckoned to minimize wrinkles and stretch marks.

Information about medicinal qualities of plants, or about their use as medicines, is for interest only, and is not intended to be used as a guide for the treatment of medical conditions.

Photograpns taken near the West Point road, 2014
Page last updated 4th April 2019