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Plant Database

Search for native plants by scientific name, common name or family. If you are not sure what you are looking for, try the Combination Search or our Recommended Species lists.

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Ambrosia ×helenae

Ambrosia ×helenae Rouleau

Ragweed, Helen Ragweed

Asteraceae (Aster Family)


USDA Symbol: AMHE3

USDA Native Status: L48 (N), CAN (N)

Natural hybrid between Ambrosia artemisiifolia and Ambrosia trifida.


From the Image Gallery

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Plant Characteristics

Duration: Perennial
Habit: Herb
Size Notes: Up to about 5 feet tall.
Fruit: Fruit is a cypsela (pl. cypselae). Though technically incorrect, the fruit is often referred to as an achene.

Bloom Information

Bloom Color: White , Yellow , Green
Bloom Time: Jul , Aug , Sep , Oct , Nov
Bloom Notes: Flowers are inconspicuous and without ray florets.


USA: AR , CT , IA , IL , MI , NY , OH
Canada: ON , QC

Web Reference

Webref 3 - Flora of North America (2014) Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.

Additional resources

USDA: Find Ambrosia ×helenae in USDA Plants
FNA: Find Ambrosia ×helenae in the Flora of North America (if available)
Google: Search Google for Ambrosia ×helenae


Record Modified: 2018-12-11
Research By: CBR

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