BugwoodWiki Article

tansy ragwort
Senecio jacobaea L.

Overview

Appearance
Senecio jacobaea is a biennial to short lived perennial herb native to Eurasia. Plants can reach 1-4 ft. (0.3-1.2 m) tall.
Foliage
The leaves of the basal rosette have petioles, cauline (stem) leaves are sessile and both are deeply lobed and alternate. The leaf lobes are oblong and web-shaped. The margins of the leaves are dentate. The leaves can measure between 1.5-8 in. (4-20 cm) long and 0.75-2.25 in. (2-6 cm) wide. The leaf is medium green above, lighter underneath and occasionally tomentose.
Flowers
Flowering occurs in summer to early fall, when numerous yellow, daisy-like flowers develop in a flat topped inflorescence at the apex of the stems. Flower heads are 0.8 in. (2 cm) in diameter.
Fruit
Fruit are small and have a persistent ring of white hairs (pappus) attached. 60,000-70,000 seeds produced per plant. Seeds can remain viable for up to 15 years.
Ecological Threat
S. jacobaea invades rangelands in the West where it is toxic to livestock. In the East it invades pastures, open forests, swamps, riverbeds, coastal grasslands and disturbed areas. It was first reported in the United States in the early 1900’s. It is native to most of Europe, North Africa and western Asia and may have been introduced into the United States as a medicinal plant.

Resources

Selected Images


5436134
5436134

tansy ragwort
Senecio jacobaea
Plant(s)
Eric Coombs
1196241
1196241

tansy ragwort
Senecio jacobaea
Plant(s)
Faith Duncan
5449718
5449718

tansy ragwort
Senecio jacobaea
Foliage
Leslie J. Mehrhoff
5374545
5374545

tansy ragwort
Senecio jacobaea
Foliage
Joseph M. DiTomaso
1196221
1196221

tansy ragwort
Senecio jacobaea
Flower(s)
Michael Shephard
5274073
5274073

tansy ragwort
Senecio jacobaea
Fruit(s)
Leslie J. Mehrhoff
5308094
5308094

tansy ragwort
Senecio jacobaea
Plant(s)
USDA PLANTS Database
5449688
5449688

tansy ragwort
Senecio jacobaea
Infestation
Leslie J. Mehrhoff
0023035
0023035

tansy ragwort
Senecio jacobaea
Infestation
Eric Coombs

Maps


EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org

EDDMapS Distribution

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit Invasive.org

State Regulated List

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Subclass: Asteridae
Order: Asterales
Family: Asteraceae
Genus: Senecio

Other System Links

Plants: SEJA
Bayer: SENJA
GRIN: 104534
ITIS: 36089
NPDN Pest: PBFCXBC

Synonyms and Other Names

Other Common Names:
ragwort, stinking Willie

Categories

Category: Forbs/Herbs