Intruder In The Garden

While hunting the dandelions in the garden, I came across this vibrant rosette right there snuggled next to a strawberry plant.
This is the weed called tansy (tansy ragwort) and is a noxious weed that that can be deadly to horses and cattle when ingested.
Washington State Noxious Weed website has been useful in identifying those invaders that I need to be on the lookout for around the farm. The site gives clear pictures of the species from emergence to dried elders and detailed descriptions.

Why Is It a Noxious Weed?

Tansy ragwort is toxic and a threat to livestock and agriculture. All plant parts are toxic, with the highest amount of alkaloids in flowers then leaves, roots and stems. Toxic properties are a possible threat to humans through food chain contaminants.

How would I identify it?

General Description

It is a biennial to sometimes annual or perennial herbaceous plant. As a biennial, tansy ragwort spends the first year in the rosette stage with dark green basal leaves that appear ruffled. During the second year, one or two flowering stems form.

Flower Description

Flowerheads are in flat topped clusters. Flowerheads yellow with many disk flowers and 13 ray flowers, overall flowerhead daisy-like in appearance. Flower heads have around 13 bracts at their base with dark tips.

Leaf description

Leaves are twice divided, with petioles on leaves near the base and without petioles toward stem tips. First year leaves in a basal clump (rosette). Second year leaves are alternate along the stem, 1.6 to 7.9 inches long by 0.8 to 2.4 inches wide.