Common ragweed is a summer annual broadleaf weed that produces a high amount of pollen and is a highly competitive species. Ragweed is a species whose pollen is implicated in human allergies. This broadleaf weed does well in poor soil conditions that are low in nitrogen, phosphorus and potassium.
The cotyledons of Common Ragweed are oblong in shape with leaves that have a purple underside and grow opposite one another. As the plant matures, its leaves will become alternate. Hypocotyls (main stem) are green with purple spots (in most instances).
Leaves can be distinguished through finely divided growth, are egg shaped and range from 4-10 cm in length. Stems grow erect with branching and grow long rough hairs. Fruits are yellow to brown in colour and are made of 4-7 projections that give them the appearance of a crown. Male flowers are found in the upper portions of the plant and female flowers are in the lower regions. Common ragweed can range from 20-250 cm in height.
Optimal growth conditions
The species Ambrosia artemisiifolia is commonly found in waste areas and it prefers full sunlight with low pH and high soil nutrients. The plant can also withstand dry conditions.