Senecio jacobaea
Senecio viscosus
stinking willie, tansy ragwort
stickly groundsel, sticky ragwort
sparsely and unevenly tomentose, glabrescent except in leaf axils and among heads.
densely fetid-viscid (hairs glandular).
(often purplish-tinged) usually single, sometimes loosely clustered.
single.
± evenly distributed (basal often withering before flowering); petiolate (sometimes obscurely);
blades ovate to broadly ovate (usually 1–3-pinnate, lobes mostly obovate to spatulate), (4–)7–20(–30) × (1–)2–5(–12) cm, bases usually tapered, ultimate margins dentate (distal leaves similar, smaller).
evenly distributed; petiolate;
blades obovate to oblong (pinnately dissected to pinnatifid), 2–7 × 1.5–4 cm, bases tapered or ± truncate, ultimate margins wavy or crenate-dentate (distal leaves sessile, smaller, ± clasping).
± 13;
corolla laminae 8–12 mm.
± 13;
corolla laminae 1–2 mm (usually coiled, scarcely surpassing phyllaries).
± 13, 3–4(–5) mm, tips black or greenish.
(± 13) ± 21, 5–7 mm, tips black.
of 2–6 (inconspicuous) bractlets (less than 2 mm).
of 2–5 bractlets (largest to 4 mm).
(10–)20–60+ in corymbiform arrays.
(1–)3–8(–30) in irregular, corymbiform arrays.
all sparsely hairy or ray cypselae glabrous.
usually glabrous, sometimes hairy.
= 40.
= 40.
Senecio jacobaea
Senecio viscosus
Senecio jacobaea is a weed introduced from Europe and now well established in places of cool, damp summers. It is toxic to livestock and legally noxious in most states and provinces where it occurs.
The Russian botanist E. Wiebe (2000) resuscitated Jacobaea for plants that are treated here as Senecio jacobaea, S. erucifolius, and S. cannabifolius. Phylogenetic studies may confirm the utility of recognizing Jacobaea as a distinct genus; to do so here would be premature.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Senecio viscosus is a smelly, Eurasian weed now widely scattered in areas of cool damp climates, often as a casual waif. The viscid hairs trap wind-blown particles of sand, dust, and soot, which give the surfaces varying textures and colors.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
Go Botany, 
IL Wildflowers, 
MI Flora, 
PNW Herbaria, Turner Photog. 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
MN Wildflowers
