Senecio jacobaea

Species category

Weed

Common name

stinking willie

Diagnostic characters

Planting unit

AcheneAchene:
A dry, hard, one-chambered, one-seeded indehiscent fruit, as in buckwheat (Fagopyrum) or sunflower (Helianthus). The fruit wall is not united with the seed coat.

Shape

Rectangular

Size

  • Length 3 mm
  • Width 0.5 mm
  • Thickness 0.5 mm

Color

Light brown

Texture

Short, appressedAppressed:
Pressed close or lying flat against something.
hairs on the ribs

Other structures

Thick longitudinal ribs, a distinct apicalApical:
The distal end of the fruit or seed away from the point of attachment or attachment scar.
collar, and a wide scar.

Identification notes

There is little space between the ribs. There is an apicalApical:
The distal end of the fruit or seed away from the point of attachment or attachment scar.
collar surrounding the stylarStylar:
The end of the fruit or seed that contains the style or the apical end.
lobe. Some of the achenesAchene:
A dry, hard, one-chambered, one-seeded indehiscent fruit, as in buckwheat (Fagopyrum) or sunflower (Helianthus). The fruit wall is not united with the seed coat.
shown are in a state of deterioration.

Noxious weed seed categories

State Noxious Weed: California, Idaho, Montana, Oregon

AOSA examination list

Not included

Nomenclature

Family

Asteraceae

Valid name

Senecio jacobaea L.

Synonyms

Jacobaea vulgaris Gaertn.

 Senecio jacobaea.  Light brown achenes with short, appressed hairs on the ribs.
Senecio jacobaea. Light brown achenes with short, appressed hairs on the ribs.
 Senecio jacobaea.  Light brown achenes with thick longitudinal ribs, a distinct apical collar, and a wide scar. 
Senecio jacobaea. Light brown achenes with thick longitudinal ribs, a distinct apical collar, and a wide scar.