Cypress spurge (Euphorbia cyparissias) is native to Europe and western Asia but not to North America. It was imported, cultivated as an ornamental, and sold in nurseries for use in gardens, parks, and graveyards. It escaped cultivation and is now naturalized across the United States and southern Canada. It is considered invasive and is on the state noxious weed list of 46 states including Wisconsin, but does not show up on any list of invasive or noxious species in Minnesota.
The latex exuded by broken stems and leaves of this plant causes a rash in some people similar to that of poison ivy. The plant may be also toxic to cattle and horses.
Cypress spurge is similar in appearance to another invasive plant, leafy spurge (Euphorbia esula). Cypress spurge is a much smaller plant with smaller, very crowded leaves.