Arctotheca calendula

Species category

Weed

Common name

Capeweed

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

ObovateObovate:
Inverted egg shaped with apical end the broadest.

Size

  • Length: 3.5 mm
  • Width: 2.5 mm
  • Thickness: 2 mm

Color

Dark brown

Texture

Ribs short and transverseTransverse:
Set crosswise, crossing or at right angles.
and sometimes woolly pubescentPubescent:
Having hairs.

Other structures

Collar remnants on apicalApical:
The distal end of the fruit or seed away from the point of attachment or attachment scar.
end

Identification notes

Ribs short and transverseTransverse:
Set crosswise, crossing or at right angles.
; sometimes woolly pubescentPubescent:
Having hairs.
.

Comments

Apical collar is somewhat flared.

Noxious weed seed categories

State Noxious Weed: California
Federal

Learn more on ITP's Federal Noxious Weed Disseminules tool.

AOSA examination list

Not included

Nomenclature

Family

Asteraceae

Valid name

Arctotheca calendula (L.) Levyns

 Arctotheca calendula.  Obovate seed, sometimes woolly pubescent.
Arctotheca calendula. Obovate seed, sometimes woolly pubescent.
 Arctotheca calendula.  Achenes with short and transverse ribs.
Arctotheca calendula. Achenes with short and transverse ribs.
 Arctotheca calendula.  Fruit with hairs teased back to better reveal the fruit. Photo courtesy of USDA-APHIS-PPQ.
Arctotheca calendula. Fruit with hairs teased back to better reveal the fruit. Photo courtesy of USDA-APHIS-PPQ.