Common Tansy

Common tansy Tanecetum vulgare L. Sunflower family
Key identifying traits Flower heads have numerous yellow ¼ to ½ inch button-like flowers without any ray petals and clustered in flat-topped crowns Leaves are divided into many leaflets which are serrated on the margins Stems are 1 ½ to 6 feet tall and often purplish-red in color Plants are highly aromatic Biology and ecology A perennial plant reproducing by seeds and root stalks Can form very dense patches in moist areas; found along roadsides, in waste areas and in pastures usually with good subsoil moisture Undesirable as a livestock forage Sometimes mistaken for Tansy ragwort which is poisonous to livestock (Tansy ragwort has ray flowers and a coarser leaf and is usually found west of the Cascades) Introduced as a medicinal herb and ornamental Control Prevention – Learn to identify plants; know your property; beware of fill dirt, hay and seed from outside your area Biological – None known at this time Cultural – Healthy competitive vegetation helps lessen chance of invasion but doesn’t preclude it Mechanical – repeated tillage or digging can be effective but must wear out rootstocks Chemical – Several effective at label rates with best application time dependant on the herbicide used; refer to the PNW Weed Management Handbook for specific chemical recommendations	common tansy plants in bud stage
	common tansy flowers
	tansy ragwort flowers

*Where found –* Common in the US. Also, throughout Stevens County usually in dense patches in sub-irrigated areas along roads, ditches, in waste areas and in pastures. MSdoc pdf