Iva axillaris

Species category

Weed

Common name

povertyweed, deer-root, poverty sumpweed, lesser marshelder, mouseear povertyweed, poverty weed, smallflowered marshelder

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 2–2.5 mm
  • Width 1.2–1.8 mm
  • Thickness 0.8–1 mm

Color

Light brown with yellow flaking

Texture

Rough and dull

Other structures

Scar is basalBasal:
The base of the fruit or seed opposite the apical end.
. ApicalApical:
The distal end of the fruit or seed away from the point of attachment or attachment scar.
style lobe present.

Identification notes

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.
broadly obovateObovate:
Inverted egg shaped with apical end the broadest.
, somewhat three-sided, with two sides flattened and one side rounded. Color is yellow to gray-black with a dull and rough surface texture. ApicalApical:
The distal end of the fruit or seed away from the point of attachment or attachment scar.
rim is rounded or inconspicuous.

Noxious weed seed categories

State Noxious Weed: California, Colorado, Utah, Washington, Wyoming 

AOSA examination list

Included

More information

For more information, see ISMA fact sheet.

Nomenclature

Family

Asteraceae

Valid name

Iva axillaris Pursh

Synonyms

Iva axillaris Pursh ssp. robustior (Hook.) Bassett
Iva axillaris Pursh var. robustior Hook.

 Iva axillaris.  Achenes are yellow to gray- black with a dull and rough surface texture. 
Iva axillaris. Achenes are yellow to gray- black with a dull and rough surface texture. 
 Iva axillaris.  Looking down on the bases of two fruits. The fruit attachment scar is thin and often crescent-shaped. Photo courtesy of USDA-APHIS-PPQ.
Iva axillaris. Looking down on the bases of two fruits. The fruit attachment scar is thin and often crescent-shaped. Photo courtesy of USDA-APHIS-PPQ.