Photo Credit: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Management Category
Squamish
Whistler
Pemberton
Vectors of Spread
ID Characteristics
Cypress spurge is a perennial plant. The above-ground vegetation dies back annually, while the plant’s root and crown overwinter underground.
Flowers: Small, greenish-yellow female and male flowers clustered into an umbrella-shaped cluster, called an umbel. These flowers form dense bushy stands.
Stems: Grow to between 10 – 60 cm and are branch-less. Stems and leaves exude a milky, toxic sap when broken.
Leaves: Thin, waxy and blue-green, 2.5 – 3 cm long. The leaves grow in an alternate pattern along the stem, or in a spiral (whorl). Branch leaves are needle-like and narrower than stem leaves.
Seeds: Seed capsules are 3 mm long, grey, grooved and oval-shaped. They contain pale yellow, hairy (glabrous) seeds.
Similar Species
Invasive
Leafy spurge (Euphorbia esula) is often confused with cypress spurge, as it is a perennial that can grow up to 0.8 m tall with greenish-yellow flowers and leaves arranged in a spiral (whorl) on the stem. Like cypress spurge, it contains a white milky latex that can be toxic to humans and livestock. Unlike cypress spurge, it is much taller and robust, with fewer, wider leaves. Both spurges are invasive.
Habitat and Origin
Cypress spurge is native to Europe and Western Asia. It was brought to North America as a garden ornamental.
Cypress spurge is commonly found in dry, gravel roadsides, pastures, and meadows. This plant thrives in open, disturbed areas with stony, sandy or dry soils. While it prefers direct sunlight, cypress spurge is also tolerant of shade.
How it Spreads
Cypress spurge reproduces predominantly by seed, but roots can also form new, genetically identical plants by creeping rhizomes (horizontal roots that grow outward and send up clones). It can also form new plants from root fragments. Cypress spurge has a rapid regeneration time.
Cypress spurge can be locally spread by vegetative reproduction through its root system, but long-distance dispersal occurs through the transport of seeds. Wind predominantly spreads the seeds, but water, animals, and humans (via clothing, vehicles, etc.) may also aid in the plant’s spread. Note that cultivating cypress spurge can contribute to its spread, as root pieces can get caught on machinery and be transported to new locations.
Impacts
Ecological:
- Alters native grassland biodiversity.
- Displaces wildlife and livestock by eliminating forage areas due to dense colonies.
- Crowds out pastures.
- Decreases moisture and nutrients in soil.
Health:
- Contains a milky latex that can irritate the skin of humans, as well as the skin and mouths of livestock.
Economic:
- Reduces the abundance of desirable vegetation.
- Reduces cattle grazing and hay production capacities.
- Reduces the value of pastures; contaminates hay fields.
Prevent the Spread
Cypress spurge is present in certain portions of the Sea to Sky region but has not yet infested all potential habitats. The goal is to contain the spread of cypress spurge to Squamish and Whistler (ISMA 1 and 2).
Help us contain cypress spurge by reporting sightings on our website.
DO:
- Regularly monitor properties for weed infestations.
- Ensure soil and gravel is uncontaminated before transport.
- Minimize soil disturbances (e.g. use grazing plans that prevent soil exposure from overgrazing), and use seed mixes with dense, early colonization (e.g. alfalfa or barley) to re-vegetate exposed soil and resist invasion.
- Minimize soil disturbance in the area surrounding an infestation.
- Ensure plants (particularly flowering heads or root fragments) are bagged or covered to prevent spread during transport to designated disposal sites (e.g. landfill).
DO NOT:
- DO NOT plant cypress spurge in a garden, no matter how well-contained its enclosure may seem.
- DO NOT move soil that has been contaminated with cypress spurge.
- DO NOT unload, park, or store equipment or vehicles in infested areas; remove plant material from any equipment, vehicles, or clothing used in such areas and wash equipment and vehicles at designated cleaning sites before leaving infested areas.
- DO NOT mow or weed-whack cypress spurge, as the fragments can propagate as new colonies. Frequent mowing may also accelerate shoot development, leading plants to spread laterally from the parent plant.
- DO NOT compost cypress spurge.
Control
Mechanical Control
- Hand-pull infestations when the soil is moist, removing the entire root system.
- Mowing or tilling at regular intervals (every 3 weeks) can adequately reduce weed progression at first bloom, but this can stimulate new growth if the mowing is not done regularly. Additionally, note that mowing will not eradicate the plant.
- Remember to wear gloves when handling cypress spurge, since the sap is irritating to the skin.
Chemical Control
- Annual applications of dicamba or 2,4-D, or monthly applications of glyphosate, have proven effective.
- On small infestations, picloram or a combination of picloram and 2,4-D is also effective, but please note that picloram is not suitable for wet, coastal soils.
- We recommend that any herbicide application be carried out by a person holding a valid BC Pesticide Applicator Certificate. Before selecting and applying herbicides, you must review and follow herbicide labels and application rates; municipal, regional, provincial and federal laws and regulations; species-specific treatment recommendations, and site-specific goals and objectives.
Biological Control
Flea beetles (Aphthona cyparissiae and A. nigristucus) feed on cypress spurge’s roots, providing control; grazing by sheep and goats has also been reported as successful.
Sea to Sky Distribution
Cypress Spurge Factsheet
Having trouble viewing the factsheet? Don’t worry, all the information is included on this page. You can also contact us with any questions.
References
- Electronic Atlas of the Flora of British Columbia, Euphorbia cyparissias
- Faubert, H. and R.A. Casagrande, “Cypress Spurge” in Biological Control of Invasive Plants in the Eastern United States
- Fraser Valley Invasive Species Society, Cypress Spurge
- Government of BC, Hyles euphorbiae
- Invasive Plant Atlas of the United States, Cypress Spurge
- Invasive Species Council of BC, Cypress Spurge
- Lillooet Regional Invasive Species Society, Cypress Spurge (Euphorbia cyparissias)
- Northwest Invasive Plant Council, Cypress Spurge
- Peace River Regional District, Cypress Spurge
- US Department of Agriculture Fire Effects Information System, Euphorbia cyparissias