Knautia arvensis

Species category

Weed

Common name

field scabiosa

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

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.
are spatulateSpatulate:
Having a narrow base and rounded apex. Pear-shaped.
and enclosed in the flower base.

Size

  • Length 7–9 mm
  • Width 2–3 mm
  • Thickness 2–3 mm

Color

Brown

Texture

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.
are enclosed in united petal bases.

Other structures

Achene apexApical:
The distal end of the fruit or seed away from the point of attachment or attachment scar.
has lateral spikesSpike:
Has a strong central axis (rachis) on which flowers or spikelets are directly attached (sessile), e.g. wheatgrasses.
.

Identification notes

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.
has a long neck. Units usually include the base of the composite flower.

Noxious weed seed categories

Not listed

AOSA examination list

Not included

More information

For more information, see ISMA fact sheet.

Nomenclature

Family

Dipsacaceae

Valid name

Knautia arvensis (L.) J.M. Coult.

Synonyms

Scabiosa arvensis L.

 Knautia arvensis.  Achenes with a long neck and spikes at the apex. Achenes are enclosed in united petal bases.
Knautia arvensis. Achenes with a long neck and spikes at the apex. Achenes are enclosed in united petal bases.