Euphorbia maculata, commonly known as Spotted Spurge, is a ubiquitous, fast-spreading annual weed found globally in lawns, gardens, and sidewalk cracks. This low-growing plant belongs to the diverse Euphorbiaceae family, which includes the poinsettia. Spotted Spurge is not edible and is considered toxic to humans and pets. Its presence is a concern due to its aggressive growth and the irritant properties found throughout the plant.
Identifying Spotted Spurge
This summer annual is recognized by its distinctive prostrate growth habit, forming dense, flat mats up to three feet in diameter from a central taproot. The stems are reddish or pink, often covered with fine hairs, and hug the ground, making mowing ineffective for control. Its small, oblong leaves grow opposite one another along the stems and are dark green, sometimes featuring slightly toothed edges.
A key identifying characteristic is the dark, reddish-purple spot, or macula, frequently found near the center of each leaf, which gives the plant its common name. When any part of the stem or leaf is broken, a milky white substance called latex immediately oozes out. Although the plant produces tiny, inconspicuous greenish-white flowers, identification relies most heavily on the mat-forming habit, the purple leaf spot, and the reddish, hairy stems.
The Toxic Mechanism: Understanding the Sap
The milky white latex that exudes from any damaged part of the Spotted Spurge is the source of its toxicity, a defense mechanism common to the Euphorbia genus. This sap is a complex emulsion containing various chemical compounds, most notably potent irritants known as diterpene esters. These compounds are responsible for the caustic and inflammatory reactions upon contact.
The mechanism of toxicity is direct irritancy, where the diterpene esters cause damage to the cell membranes they encounter. This chemical action triggers a strong inflammatory response in the skin and mucous membranes. The high concentration of these irritants means that even a small amount of sap can cause a reaction.
Health Consequences of Exposure
Exposure to Spotted Spurge results in two types of health consequences: external contact effects and internal ingestion effects. Direct contact with the milky latex on the skin can cause contact dermatitis, manifesting as redness, itching, and swelling. In some cases, exposure followed by sunlight can lead to a delayed, more severe reaction, including blistering.
Contact with the eyes is serious, as the caustic sap can cause severe pain, intense irritation, and conjunctivitis. Accidental contact requires immediate decontamination to prevent potential temporary damage to the cornea. Ingestion of the plant, though usually causing low-severity poisoning, can lead to significant gastrointestinal distress. Symptoms of internal exposure include nausea, severe vomiting, stomach pain, and diarrhea. Suspected consumption by small children or pets requires immediate medical or veterinary attention.
Safe Handling and Disposal
When removing Spotted Spurge, minimizing contact with the plant’s sap is the most important safety protocol. Always wear protective clothing, including long sleeves, long pants, and sturdy, impermeable gloves to prevent skin exposure. Eye protection, such as safety goggles, is advisable to guard against accidental sap splatters when pulling the plant.
Because the plant can regenerate from its deep taproot, extract the entire root system. The removed plant material should be bagged and discarded into the regular trash rather than being added to a compost pile. Composting the weed risks spreading its seeds and exposing other materials to the toxic sap. Prevent pets and small children from accessing areas where the weed is prevalent or where removal activities are taking place.