This species is also referred to as the balsam-spurge, graveyard-weed, Bonaparte's-crown, tree-moss, quacksalver's-spurge.
The cypress spurge is a bright green, smooth perennial plant with small brownish scales below and numerous narrow green leaves above. Each branch is surmounted by an umbel of many rays, with a circle of linear leaves subtending it. The flowers are small, each protected by large heart-shaped, yellow bracts. The plant is in bloom from May to September.
This species has also been introduced into Canada from Europe, and has escaped from gardens to roadsides and waste places.
The whole plant is similarly poisonous to the preceding species. The milky juice irritates the skin and raises blisters, and sometimes causes serious inflammation. Cattle avoid the plant, but have been accidentally poisoned by drinking from water into which it had been thrown.
Remedy and Means of Control: Small patches of this weed should be grubbed out and the rootstocks destroyed by the application of hot brine or caustic soda. On larger areas, close cutting when the plants are in full bloom will in time starve the rootstocks.