Alternanthera sessilis

Species category

Flower, Herb, Weed

Common name

sessileSessile:
A flower or spikelet with no pedicel therefore attached directly to the central axis (rachis) or other surfaces.
joyweed, okulabeluulechad (Palau)

Diagnostic characters

Planting unit

True seedTrue seed:
A mature fertilized ovule consisting of an embryo, with or without and external food reserve (e.g., endosperm) enclosed by the testa.

Shape

Discoid

Size

  • Length: 1–1.2 mm
  • Width: 0.9–1 mm
  • Thickness: 0.4–0.6 mm

Color

Brown

Texture

Smooth

Other structures

Linear embryoEmbryo:
A rudimentary plant contained in a seed, usually consisting of a more or less differentiated axis and attached cotyledon(s).
is visible surrounding dark brown perispermPerisperm:
Nutritive tissues occurring within certain seeds, derived from the nucellus; similar in function to endosperm.
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Identification notes

Seeds borne singly in granularGranular:
Resembling or consisting of small grains or particles.
-coated fruitsFruit:
A mature ovary and any associated parts.
which are in turn surrounded by six triangular glumesGlume:
The pair of chaffy bracts that occur at the base of a grass spikelet, often completely enclosing it.
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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

Amaranthaceae

Valid name

Alternanthera sessilis (L.) R. Br. ex DC.

Synonyms

Achyranthes sessilis (L.) Desf. ex Steud.
Alternanthera glabra Moq.
Gomphrena sessilis L.

 Alternanthera sessilis.  Granular-coated fruits surrounded by six-pointed glumes. Photo by Julia Scher, USDA-APHIS-PPQ.
Alternanthera sessilis. Granular-coated fruits surrounded by six-pointed glumes. Photo by Julia Scher, USDA-APHIS-PPQ.
 Alternanthera sessilis.  Discoid true seed. A linear embryo is visible surrounding a dark brown perisperm. Photo by Julia Scher, USDA-APHIS-PPQ.
Alternanthera sessilis. Discoid true seed. A linear embryo is visible surrounding a dark brown perisperm. Photo by Julia Scher, USDA-APHIS-PPQ.