About Euphorbia heterophylla L.
Euphorbia heterophylla L. grows between 30 and 100 cm tall. It has hollow stems that may be branched or unbranched, marked with angular ribs. Its leaves have variable shapes both within individual plants and between different populations. Lower leaves are arranged alternately, while upper leaves are opposite, and their bases are commonly whitish or bright red. This plant can flower within 30 days after emergence, and ripe seeds form 25 to 30 days after flowering. It is pollinated by insects that are attracted to the large amounts of nectar it produces. Extrafloral nectaries located at the flowers of E. heterophylla were first reported by Zimmerman in 1932. The plant’s stalk exudes a toxic milky white latex. Its false flowers, called cyathia, grow in clusters at the top of the stalk, and are yellowish green. Cyathia have no petals, and any visible red coloration comes from the coloring of the plant’s young leaves. The fruits of this species are small, segmented capsules. When the fruits reach maturity, they explode and shoot seeds some distance away from the parent plant, enabling seed dispersal. This plant often loses its characteristic coloration when it grows as a wild weed. Populations of E. heterophylla with resistance to specific herbicides have been identified in South America. Euphorbia heterophylla is native to tropical and subtropical America, but is now widespread across all tropical regions. Many herbicides do not work to control it, so it has spread rapidly across many parts of the world. It was introduced to South and Southeast Asia as an ornamental plant, and has since become an invasive weed in India and Thailand, where it invades cotton fields and other agricultural land. Toxicity is documented for most species in the genus Euphorbia. People who are sensitive to latex can experience strong reactions, including dermatitis and anaphylaxis, from contact with the latex this plant exudes.
