Flower primary purpose of a flower is reproduction. Since the flowers are the reproductive organs of plant, they mediate the joining of the sperm, contained within pollen, to the ovules — contained in the ovary. Pollination is the movement of pollen from the anthers to the stigma. The joining of the sperm to the ovules is called fertilization. Normally pollen is moved from one plant to another, but many plants are able to self pollinate. The fertilized ovules produce seeds that are the next generation. Sexual reproduction produces genetically unique offspring, allowing for adaptation. Flowers have specific designs which encourages the
Parthenium hysterophorus production, an additive in manure for biogas production, as a biopesticide, and as green manure and compost. Contact with the plant causes dermatitis and respiratory malfunction in humans, and dermatitis in cattle and domestic animals. The main substance responsible is parthenin, which is dangerously toxic. It also is responsible for bitter milk disease in livestock when their fodder is polluted with "Parthenium" leaves. Among other allelopathic effects of the species, the presence of "Parthenium" pollen grains inhibits fruit set in tomato, brinjal, beans, and a number of other crop plants. Light infestations of "Parthenium hysterophorus" in cultivated fields may be