Weed Management — Weedmgt Parthenium Intro
| Partheniumhysterophorus L. | ||
| Family | : | Compositeae (Asteraceae) |
| Common name | : | Congress Weed |
| Tamil name | : | Vishapoondu |
| Morphology | : | Broad leaved weed. |
| Habit | : | Annual herb, up to 1.5 m |
| Stem | : | Slender hairy |
| Leaf | : | Leaves alternate, sessile, bipinnatifid, up to 20 x 10 cm, pubescent, lobes entire, acute |
| Flower | : | Heads many, peduncled in panicles, florets white, outer florets 5, female, supported by two hyaline wings at base; inner few male florets; corolla in female an obovate, entire ligule; in male tubular, 5 lobed; anthers obtuse below |
| Fruit | : | Fruit an achene, dorsally compressed, narrowed below; pappus of 2 lateral reflexed awns |
| Propagation | : | By seed |
| Habitat | : | Cultivated fields and road side |
Parthenium ( Partheniumhysterophorus L.) also known as star weed, carrot weed, white cap, white top, etc. has been found growing naturally since centuries in Mexico, North and South America, Australia, China, Pacific islands, East and South Africa and Canada. Till 1977, the weed did not find any place in the list of world's worst weeds. But, within the last decade, it has become one of the seven most dreaded weeds of the world.