Cypress Spurge
Euphorbia cyparissias

Name and Family

Cypress Spurge, Euphorbia cyparissias, is a member of the spurge family (Euphorbiaceae).

Cypress spurge is a Eurasian native, likely introduced to North America in the early 1800’s as an ornamental garden plant.
It has attractive yellow-green flowers and a beautiful whorled leaf arrangement.
The plant may have also been introduced accidentally, as both fertile and non-fertile variants exist in North America today. This may also be due to people unintentionally growing fertile plants when they intended to plant the infertile variety.
The plant was present in New Brunswick by 1883.
Cypress spurge was traditionally planted in graveyards, giving it an alternate common name, “graveyard weed”.
Over the past century, the plant has spread through ornamental planting, movement of contaminated hay, and being carried on contaminated farm equipment. Today it exists in 42 states in the U.S. and throughout Canada.
Distribution and presence on PEI are unknown.

Here are some key features that may help to positively identify cypress spurge:

Cypress spurge is a herbaceous perennial plant.
It grows in open, disturbed areas such as pastures, abandoned fields, ditches and coastal areas.
Can grow to 10-40cm tall
Leaves are small, linear-shaped, 1-3cm long and 1-3mm wide, whorled around the stem
True flowers lack petals, sepals
Greenish-yellow heart-shaped bracts under flower
Flowers turn to purple-red as they mature
Blooms May – August
Mature fruit has three lobes, each containing a smooth, gray seed
Reproduces through lateral root buds
Cypress spurge is shorter and less robust than leafy spurge and has more, smaller leaves

Cypress spurge’s shade tolerance allows it to be a prolific invader of many different habitats, including sensitive areas like woodlands.
The plant is drought tolerant and prevents the growth of native species by out-competing for space, nutrients, and water.
It is a tenacious plant and has an exceptionally deep root system that allows the plant to persist and spread vegetatively. The plant is also able to reproduce by seed.
The above growth behaviours reduce local biodiversity and damage wildlife habitats and plant communities.
Seed-producing populations can produce anywhere from 30 to 900 seeds per plant annually and can even go to seed multiple times in a single season. This allows the plant to spread vigorously.
While not all varieties of cypress spruge can produce seeds, they can all reproduce vegetatively using their rhizomes.
Cypress spurge is a significant agricultural issue.
- The plant’s milky latex sap is toxic to livestock and is secreted when the plant is damaged.
- This means that as cypress spurge spreads in a pasture, it poses a danger to animals and can reduce the value and quality of pastureland.
The sap causes skin irritation in humans.

GENERAL CONSIDERATIONS

Before selecting a control method, consider:

The size of the infestation.
Your available resources.
The amount of effort you are willing/able to expend. Often, multiple control methods are used simultaneously. Consider the local ecosystem and what other organisms or ecological processes may be affected by management.
Management of cypress spurge will likely be an involved, long-term project, so be prepared to revisit the management site year after year to manage new growth.
The roots are also very deep, reaching as far as three metres into the ground.
- Many people may not be willing or able to dig that deep, meaning that the potential for resprouting from deep left-behind root fragments is a potential complication for management efforts.
When managing cypress spurge, it is important to wear protective equipment to avoid exposure to the irritating latex sap.
- Gloves and eye protection will be necessary, along with boots, long pants, and a long sleeve shirt.

PULLING/DIGGING

For small populations, hand pulling can effectively reduce the spread of cypress spurge if undertaken before the plant goes to seed.
Hand pulling can be labour-intensive and will require repeated visits (i.e. monthly) to pull any new plants coming up.
As the roots grow very deep, it will be necessary to dig out any root fragments left in the soil after pulling.
- If this is not possible, return regularly to the site to manage any new growth that may arise due to left-behind root pieces

MECHANICAL CONTROLS

Mechanical controls like mowing are not generally recommended as these controls can have a stimulating effect on the growth of a cypress spurge population.
The sticky latex sap is difficult to wash off and can gum up mechanical equipment.

CULTURAL CONTROLS

If you are in an agricultural setting where soil disturbance will not cause ecological damage, it may be best to cultivate the area repeatedly to control cypress spurge, as it does not tolerate cultivation well.

COVERING/TARPING

After clearing an area, it can be covered with a black tarp which will suffocate any new growth that may arise.
Additionally, the tarp can be covered with 8” soil and then replanted with native plants.
- Select plants that are drought tolerant that can survive in the shallow soil layer.
- Alternatively, use a biodegradable covering material such as geotextile or jute, which will degrade over time to help keep plants from desiccating after an extended period in shallow soil.

CHEMICAL CONTROLS

The PEIISC does not provide advice on chemical control measures at this time.
If using chemical controls, it is imperative that all local legislation and manufacturer’s instructions be followed during application.

FOLLOW-UP/REMEDIATION

It is imperative that all equipment be cleaned thoroughly and that all plant parts are removed from boots and clothing before leaving the area.
All plant parts, especially roots and seed heads, must be collected, bagged, and properly disposed of.
Each time you manage the site, collect, bag, mark, and dispose of all plant parts properly.
- Bag the plant material in clear plastic bags.
- Mark the bags boldly with a permanent marker. Write “INVASIVE PLANT” or “CYPRESS SPURGE” on the bags.
- If you have a place away from foot and wildlife traffic, you can dry out the material, making it much easier to move.
  - Leave the bags open and in the sun for a week to dry.
  - Only do this if you can guarantee that the plant will not be spread from where it is drying
- Double bag the bags to prevent accidental dispersal later on and protect waste handlers from the plant’s toxic properties.
- Tie the bags tightly and place them in your usual residential waste collection (THE BLACK BIN)
  - Never place invasive plants into the compost. This may allow them to become established once they reach the heap.
Collect plant parts in clear plastic bags marked with “invasive plant” or “cypress spurge”.
As this plant is toxic, it would be well advised to double bag the plants to prevent any accidental dispersal during transit and help keep any waste handlers safe.
For loads larger than what would fit into a ½ ton truck, contact the PEIISC for specific disposal instructions.