Tansy Ragwort ((Senecio jacobea L.)

Status:

Listed Noxious Weed In Montana

History:

First Montana Specimen Collected 1

County:

Mineral

Year:

1979

“The first recorded site of tansy ragwort in western North America was on Vancouver Island in 1913 and in Oregon in 1922. Tansy ragwort is now found from northwestern California to British Columbia, from coastal areas continuing east of the Cascade Mountains (Sweeney et al. 1991). The economic impact of tansy ragwort in Oregon during the 1970's included: more than $4 million a year lost in livestock poisoning; the loss of five to ten percent of cattle herds, and dairies were forced to close (Rees et al. 1996).” (WWCB)

Habitat:

Growth Habit:

Biennial or short-lived perennial, erect branched near top. Reproduces by seed only.

Leaves:

Alternate, deeply lobed with irregular margins, terminal lobe larger than lateral ones,
cobwebby hairs in early growth stages.

Stem:

Simple, usually single, to 6 ft. tall.

Flower:

Flower heads yellow, numerous, in clusters, about 1 inch in diameter.

Roots:

Small to medium taproot.

Seeds:

Small, striped, with a protrusion atone end.

Other Notes: