Goatweed, Tropical whiteweed
Ageratum conyzoides
Family: Asteraceae or Compositae
What it is like
Ageratum conyzoides is a ANNUAL growing to 1 m (3ft 3in). See above for USDA hardiness. It is hardy to UK zone 9. It is in leaf from May to October, in flower from July to September. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It prefers moist soil.
Height (m): 1
Where it is found
A common weed of cultivated ground, having spread from its native range to all areas of the Tropics within 20° of the Equator, to an altitude of 2,500 metres.
S. America.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 0
Medicine
Rating: 3
The plant contains between 0.7 - 2.0% essential oil, plus alkaloids and saponins. The whole plant is antiinflammatory and antiallergic. The juice of the fresh plant, or an extract of the dried plant, is used in the treatment of allergic rhinitis and sinusitis. The juice of the fresh plant is also useful in treating post-partum uterine haemorrhage. The juice of the root is antilithic. A paste of the root, mixed with the bark of Schinus wallichii, is applied to set dislocated bones. The leaves are styptic. They are dried and applied as a powder to cuts, sores and the ruptures caused by leprosy, The powder absorbs the moisture of the disease and forms a layer that is removed after 1 - 2 days. An effective cure for most cuts and sores, though it does not effect a complete cure for leprosy. The leaves are also used externally in the treatment of ague. The juice of the plant is used to treat cuts, wounds and bruises. A paste of the leaves is used as a poultice to remove thorns from the skin. A paste made of the leaves mixed with equal amounts of Bidens pilosa, Drymaria cordata, Galinsoga parviflora and the rhizome of Zingiber officinale is used to treat snakebites. The juice of the flowerheads is used externally to treat scabies, whilst a paste of them is used to treat rheumatism. A tea made from the flowerheads mixed with Ocimum tenuifolium is used to treat coughs and colds.
Antiinflammatory: Reduces inflammation of joints, injuries etc.
Leprosy: Used to treat leprosy - a chronic bacterial infection of the skin and superficial nerves (in the skin) caused by Mycobacterium leprae.
Lithontripic: Removes stones from the kidney, bladder etc.
Skin: Plants used in miscellaneous treatments for the skin.
Styptic: An astringent that stops bleeding by contracting the blood vessels.
Vulnerary: Promotes the healing of wounds.
Other
Rating:
The leaves and the flowers yield 0.2% essential oil with a powerful nauseating odour. The oil contains 5% eugenol, which has a pleasant odour. The oil from plants growing in Africa has an agreeable odour, consisting almost entirely of eugenol. A decoction of the fresh plant is used as a hair wash, leaving the hair soft, fragrant and dandruff free.
Essential: Essential oils that are used in perfumery, medicines, paint solvents, insect repellents etc.
Hair: Plants used as hair shampoos, tonics, to treat balding etc.
Scented Plants: Plants noted for their scent
How it is grown
Succeeds in full sun in a sheltered position in any reasonably fertile moisture-retentive soil that does not dry out in the summer. Plant vigour and flowering periods are much reduced on dry soils. This species is not frost hardy, though it can be grown as a summer annual in Britain. The fresh plant is malodorous.
Propagating it: Seed - sow late winter or early spring in a warm greenhouse and only just cover the seed. Prick out the seedlings when large enough to handle and plant out after the last expected frosts. Seed can also be sown in situ in the spring and, for earlier blooms, it is possible to sow it in late summer or early autumn, though it will need to be overwintered in a warm greenhouse.
Best place to grow: Cultivated Beds;
Habit: Annual
Hardiness: 8-11
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: No shade
Moisture: Moist