Euphorbia maculata is an annual low-growing broadleaf weed. It reproduces by seeds. The stems are slender, hairy, and reddish-pink in colour. They spread along the ground to a length of about 45-60 cm.
The plant is easily identified by its round or oblong small green leaves with reddish-purple spots in the centre and prostrate reddish-pink stems that form dense mats on the ground.
Spotted Spurge Classification
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Tracheophyta
- Subphylum: Angiospermae
- Class: Dicotyledonae
- Order: Malpighiales
- Family: Euphorbiaceae
- Genus: Euphorbia
- Species: Euphorbia maculata
- Common Names: Spotted spurge, Spotted sandmat, Spotted euphorbia, Prostrate spurge, and Milk purslane.
Nativity and Distribution
Spotted spurge is native to:
- Southeastern Canada
- East and Central United States
- Belize
- Bolivia
Today, it can also be found in Africa, Australia, and Europe.
Physical Characteristics
- Leaves: Oval to oblong with reddish-purple spots in the centre
- Fruits: 3-lobed hairy brown capsule
- Stems: Slender hairy reddish-pink prostrate stems
- Flowers: Inconspicuous small flowers with white to pink petals
- Roots: Tap root system
Euphorbia maculata is a summer annual broadleaf weed that typically grows 10 cm tall. It is easily recognized by its round or oblong small green leaves with reddish-purple spots in the centre and prostrate reddish-pink stems that form dense mats on the ground.
The stems are slender, hairy, and spread out on the ground typically reaching 45 cm long. The leaves are small, oval to oblong, opposite, about 3 cm long. They have a distinct reddish-purple spot in the centre, hence the name “Spotted Spurge”.
Spotted spurge produces small inconspicuous cup-shaped flowers that develop near the axillary bud with white to pink petals in full bloom.
The seeds are small, about 1mm long, oblong, white to light brown with an uneven and wrinkled surface.
Reproduction, Dispersal, and Life Cycle
- Life Cycle: Annual
- Seeds: A single plant can produce several thousand seeds
- Climate: A variety of climates including hot and temperate climate
- Dispersal: Wind, water, animals, and human dispersal
Spotted spurge behaves as an annual weed, thriving best in warm weather and later dying during frost conditions. The weed is a quick and prolific seed producer with a single plant producing thousands of seeds.
The seeds are hydrophilic which means they become sticky when wet and can attach to animal fur and human clothing, disseminating them to new areas. They can also be dispersed by wind, water, and contaminated agricultural tools.
Some of the dispersed seeds can begin to germinate immediately, others may sprout in the next spring season, while others may remain dormant in the soil for many years.
Similar Plants
- Euphorbia prostrata
- Euphorbia serpens
- Euphorbia thymifolia
- Euphorbia dallachyna
- Polygonum aviculare
Uses
- It is used as traditional medicine for diarrhoea, hematuria, and hemoptysis in Asia.
- The plant’s sap contains anti-inflammatory, anti-tumor, and anti-proliferative properties that are under research as a potential cure for various cancers.
Impact on Farms and Environment
While spotted spurge may have healing properties, it is generally considered a weed in most countries around the world.
Due to its prolific seed production, quick growth, and strong disease and pest resistance, Euphorbia maculata can become aggressive and difficult to control.
It is a common weed of gardens, crop fields, roadsides, pastures, sidewalk cracks, and any open space.
In landscaping settings, it reduces the uniformity and quality of turf, especially because of its extensive spread, leaving unsightly patches.
In agricultural fields, the weed impacts crops like cereals and legumes, leading to economic losses. Additionally, many parts of the plant including stems, barks, flowers, seeds, and sap are toxic and if located in pastures can lead to poisoning or death of livestock.
The weed also affects horticultural fields by reducing the growth of desirable plants and harboring destructive insects and fungal diseases that could reduce the quality of the yield.
Spotted spurge is also toxic to humans and pets. Broken stems and leaves produce a sap that causes mild to severe skin irritation or permanent damage to the cornea if it comes into contact with the eyes. If ingested, it may cause blistering on the lips, stomach irritation, and vomiting.
Control
- Mechanical control: Hand-pulling and tillage
- Cultural control: Mulching, soil solarization, and turf management
- Chemical control: Apply herbicides like pendimethalin, dithiopyr, glyphosate, triclopyr,
Hand-pulling small plants before they seed is the quickest and most effective management strategy for small infestations. Alternatively, you can till the weeds, ensuring you remove the entire plant system, including the deep root system and stem fragments to prevent regrowth.
Applying a 3-4 inch layer of bark mulch can prevent light from reaching the seedlings, starving them to death. If you prefer a prevention strategy, covering your soil for 6-8 weeks, a process known as soil solarization before planting desirable plants can significantly reduce the number of seeds that would germinate in warmer months.
Maintaining a healthy competitive turf can also prevent spotted spurge infestation. The weed targets open spaces in the grass caused by pests, disease, stress, or neglect. Once established, altering cultural practices like fertilization or irrigation will not stop the spread.
Where mulching is not feasible you can apply preemergence herbicides such as dithiopyr, isoxaben, pendimethalin, and oryzalin.
For less mature weeds, apply a postemergence herbicide with dicamba, 2,4-D, and MCPP as active ingredients. Consider non-selective herbicides like triclopyr or glyphosate for larger and more mature weeds.
Lead Editor for Insight Weeds.