Common name: Tropical whiteweed, Billygoat weed, Chick weed
It is unlikely that you’ve not seen this wild plant or weed with pretty white flowers in India. Tropical whiteweeds are native to South America, but can be seen in most countries all over the world with warm, temperate climates. In India, they are seen in grasslands, vacant plots, farms, roadsides and almost everywhere.
They grow to a height of about 1 meter with erect green, hairy stems that branch well, giving the plant a good spread. Tropical whiteweed leaves are simple, lance-like with serrations on the edges. They exude a distinct pungent smell when rubbed together or crushed.
Flowers are white, light blue or purple; small with a diameter of .6 cms growing in large bunches of about 40-60 flowers. They have a light purple tinge when the flowers are young, later turning white, dirty white and light brown before the tufts fall. Dispersal is through insects or by wind, enabling the seeds to travel long distances making sure that the plant can invade new territories.
For a plant with a life cycle of just 2 months, Tropical whiteweed is very proliferative taking over agricultural areas hampering the growth of other saplings. When conditions are favorable, they can flower year-round, producing seeds. In large agricultural farms, chemicals are used to control growth and proliferation of the tropical whiteweed so that other crops are not affected.
Propagation is through seeds.
Ageratum conyzoides: Tropical whiteweed