Sagittaria sagittifolia

Species category

Weed

Common name

arrowhead

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

OvateOvate:
Egg-shaped with basal end the broadest.
with hooked spikeSpike:
Has a strong central axis (rachis) on which flowers or spikelets are directly attached (sessile), e.g. wheatgrasses.
on apexApical:
The distal end of the fruit or seed away from the point of attachment or attachment scar.

Size

  • Length 4–5.5 mm
  • Width: 2.5–4 mm
  • Thickness: 0.5–0.7mm

Color

Light brown and gray

Texture

Striate

Other structures

Large marginal wings present.

Identification notes

Unit is compressed with a longitudinal groove on each side.

Noxious weed seed categories

Federal

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

AOSA examination list

Not included

Nomenclature

Family

Alismataceae

Valid name

Sagittaria sagittifolia L. 

 Sagittaria sagitifolia.  Ovate achene with a hooked spike on the apex.
Sagittaria sagitifolia. Ovate achene with a hooked spike on the apex.
 Sagittaria sagitifolia.  Achenes with a longitudinal groove on each side.
Sagittaria sagitifolia. Achenes with a longitudinal groove on each side.
 Sagittaria sagitifolia.  Achene with a longitudinal groove on each side. Photo by Julia Scher, USDA-APHIS-PPQ.
Sagittaria sagitifolia. Achene with a longitudinal groove on each side. Photo by Julia Scher, USDA-APHIS-PPQ.
 Sagittaria sagitifolia.  Achenes with large marginal wings. Photo by Julia Scher, USDA-APHIS-PPQ.
Sagittaria sagitifolia. Achenes with large marginal wings. Photo by Julia Scher, USDA-APHIS-PPQ.