(Chamaesyce hirta – formerly Euphorbia pilulifera)
Native to tropical America and naturalized in Northern Australia, India, and other tropical and subtropical regions, asthma plant can be found growing on river flats, waste places, and roadsides. Also commonly known as pill-bearing spurge, the plant is a semi-prostrate annual with spreading stems that grow up to 40 centimetres (19”) long. It has opposite pairs of purplish-green, ovate leaves that are up to 4 centimetres (6/8”) in length. The tiny flowers, consisting of small reddish heads, are borne in the leaf-axils and produce tiny globe shaped fruit.
Historically used for coryza (profuse discharge from the mucous membranes of the nose), hayfever, and emphysema, it is now used by professional herbalists to treat asthma, spasms of the larynx, upper respiratory catarrh, bronchitis, and anti-amoebic activity.
During the 1800s and well in to the 1900s the herb played a major role in the treatment of asthma in the former British colonies including Australia. Named after the condition that it was mostly used for the herb was prepared as a decoction or made in to a tincture. Used as folk medicine in other parts of the world including Africa and Asia for the treatment of respiratory and intestinal conditions, asthma plant also has other uses. All parts of the plant secrete large amounts of white latex (sap) when broken and is used by the Australian aborigines to remove warts. The Malaysians used the latex to treat eye conditions and they pounded the whole plant to make a poultice to treat bruises.
Much of the plants healing virtues were written about in the late 1800s and the early 1900s and it was listed in the British Pharmacopoeia until the 1950s if not later. Apart from making decoctions and tinctures from the herb, another way of obtaining its medicinal action for respiratory conditions was to smoke it or burn it and inhale the smoke. It is a strong herb so compared to many medicinal plants, the adult dose should be very small: 0.12 – 0.30 grams of the dried herb three times daily.
Harvest the plant during flowering, in late spring to autumn.