Tansy ragwort, a biennial plant, usually germinates in fall or early winter, lives through the next year as a rosette, then dies the next year after producing flowers and seeds. Its seeds have a white pappus and are wind-carried, resulting in rapid spread of tansy ragwort infestations. A single large plant may produce 150,000 seeds, which may lie dormant in the soil for as long as 15 years. The plant's fibrous system of coarse, light colored roots spreading from the crown can produce small adventitious shoots when stimulated by mechanical destruction or pulling. When prevalent, tansy ragwort is one of the most common causes of poisoning in cattle and horses, caused by consumption of the weed found in pasture, hay or silage.
Milk produced by affected cows and goats can contain toxins.
Honey from tansy ragwort also contains the alkaloids. For questions about the Water and Land Resources Web Site, please contact Fred Bentler , webmaster. By visiting this and other King County web pages, you expressly agree to be bound by terms and conditions of the site.