Robert W. Freckmann Herbarium


Because of technology changes and personnel changes at UWSP and the Wisconsin State Herbarium, the database of plant species housed at this site was merged with the database from the OLD WisFlora website to create a new Flora of Wisconsin website at Currently we are encouraging all Wisplant viewers to begin using the Flora of Wisconsin website as soon as possible. Wisplants will remain operational through July 13th. After that date, all traffic to Wisplants will be redirected to the Flora of Wisconsin website.

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  Ambrosia psilostachya DC. image
Photographer: Kenneth J. Sytsma           

Botancial Illustration

Emmet J. Judziewicz

Emmet J. Judziewicz

Emmet J. Judziewicz
Family Asteraceae
Ambrosia psilostachya DC.
perennial ragweed, western ragweed
Ambrosia: Greek for "food of the gods"
psilostachya: derived from the Greek psilos, "bare," and stachys, "a spike," hence a "bare spike"
County distribution map- click for detailed distribution maps.
Detailed Distribution:
Town Range Maps
Google Dot Maps
Status: Native
Plant: erect, perennial, 12"-40" tall forb with upper branches; creeping, fibrous roots
Flower: inflorescence of many, small, green, bead-like heads on 6" spikes; blooms Aug.-Sept.
Fruit:seeds not on fluffy pappus
Leaf:usually once pinnately-divided, lower leaves opposite, upper leaves alternate
Habitat: dry; prairies, disturbed sites; in sandy soil

More Information Natural Communities Herbarium Specimens
All Ambrosia list Google- Images or Text

Flora of North America (off site)
Ambrosia californica Rydb.
Ambrosia coronopifolia Torr. & A.Gray
Ambrosia coronopifolia Torr. & A.Gray var. asperula A.Gray
Ambrosia coronopifolia Torr. & A.Gray var. gracilis A.Gray
Ambrosia cumanensis Kunth
Ambrosia lindheimeriana Scheele
Ambrosia psilostachya DC. var. californica (Rydb.) S.F.Blake
Ambrosia psilostachya DC. var. coronopifolia (Torr. & A.Gray) Farw. ex Fernald
Ambrosia psilostachya DC. var. lindheimeriana (Scheele) Blank.
Ambrosia rugelii Rydb.

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