Latin name: Ambrosia artemisiifolia L.

Common name: Diaper ragweed, lemongrass, pheasant, American, etc.
Homeland: North America, fossil remains found in Canada over 60,000 years old.

Distribution: Cosmopolitan plant, present on all continents. The first information about the existence of ragweed on the territory of the former Yugoslavia was published in 1940. In Serbia, this species was first recorded in 1953 in the vicinity of Sremski Karlovac, Petrovaradin and Novi Sad. In the last 60 years, ragweed has spread throughout Serbia.

Description: An annual plant, 20-80 cm high, in favorable conditions can grow up to 2 meters. Stem erect in the upper part covered with hairs. The leaves are usually arranged in opposite directions on the stem, darker on the upper side, and lighter green on the lower side, covered with thick hairs, feathery, with 2 to 3 lobes. Flowers of male heads pale yellow, 10-15 in the head. Female flower single. Fruit closed.

Biology: In our ecological conditions, ragweed usually germinates and sprouts in late April and early May, and as a thermophilic plant it sprouts throughout the summer. It blooms from July to October. The seeds ripen during August and September. It is characterized by high reproductive potential, producing up to 60,000 seeds per plant of high germination over 60% and retaining the ability to germinate even over 40 years.

Significance: Ambrosia is a weed and allergen plant, as such it causes multiple damages in very different ways. It reduces the yield and quality of cultivated crops, negatively affects the health of animals and people. Ambrosia pollen – one of the most aggressive aeroallergens. One ragweed plant produces up to 45 grams of pollen per year. One gram of ragweed pollen has about 30 million pollen grains. A small number of pollen grains in the air (8-10) is enough to cause allergic reactions in sensitive people. A significant part of the human population, at the time of ragweed flowering, has pronounced symptoms of allergic sneezing, conjunctivitis, dermatitis or even allergic asthma.