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Western waterhemlock
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(Cicuta douglasii (DC.) Coult. & Rose)



Western water hemlock is generally described as a perennial. The Western water hemlock has dark green foliage and inconspicuous white flowers, with an abundance of conspicuous brown fruits or seeds. The greatest bloom is usually observed in the late spring, with fruit and seed production starting in the summer and continuing until fall. The leaves are not retained year to year. The Western water hemlock has a short life span relative to most other plant species and a rapid growth rate. At maturity, the typical plant will reach up to 6 feet high. It can be propagated by bare root, seed, and tubers. It has a moderate ability to spread through seed production.


The leaves are alternate toothed and pinnately divided. The stems grow 3-7 feet tall and are swollen at the base and the flowers are white and in compound umbels.


Western water hemlock grows only in wet places, such as along streams, ponds, irrigation ditches and marshy areas.


There are herbicides and other control methods that commonly control water hemlock. For more information on these herbicides and other control methods contact the CCWP office.


Western water hemlock is considered one of the most poisonous plants in North America and is often mistaken for water-parsnip or other edible members of this family. Several human and animal deaths have occurred. This is native to the U.S. and has its most active growth period in the spring and summer.