Common Name: Siam weed.
Siam weed is a shrub and grows to a height of about 2.5 meters. The entire plant is viscid-pubescent. The leaves are simple and arranged in opposite manner and are light green in color. Both leaf-sides are pubescent; leaf stalk measure around 1.6 cm. The leaves grow to a length of about 10.2 cm and are broadest at the base; measuring 6.1 cm. Leaf shape is triangular-rhomboid; leaf base is cuneate and apex acute. The inflorescence is a stalked corymbose cyme. Florets are pale mauve in color and tubular in shape. The fruit is the form of an elongated achene. The leaves when crushed emit a pungent aromatic smell. This plant is classified as a highly invasive plant in India. Extensively found all over Peninsular India: especially in plains and mid-altitude areas. Not commonly found in high altitude areas of Western Ghats. The seeds are wind dispersed and each plant has the potential to produce around 80000-90000 seeds in their life time. This plant is an important nectar source for butterflies.