Robert W. Freckmann Herbarium


  Toxicodendron rydbergii (Small ex Rydb.) Greene image
Photographer: Robert R. Kowal           

Botanical Illustration

Botanical Illustration

Joanne Kline

Joanne Kline

Matthew L. Wagner

Matthew L. Wagner

Matthew L. Wagner

Merel R. Black

Merel R. Black

Paul Drobot

Paul Drobot

Robert W. Freckmann

Robert W. Freckmann
Family Anacardiaceae
Toxicodendron rydbergii (Small ex Rydb.) Greene
Rydberg's poison-ivy, western poison-ivy
Toxicodendron: means "poison tree"
rydbergii: named after Per Axel Rydberg (1860-1931), a member of the New York Botanical Gardens in the late 19th and early 20th centuries, who wrote the first book on the flora of the Rockies from Canada to Mexico, and several other floras
Hazardous hazard symbol- click for definition
County distribution map- click for detailed distribution maps.
Detailed Distribution:
Town Range Maps
Google Dot Maps
Status: Native - potentially invasive
Plant: erect, perennial, 1'-3' tall shrub with 1 to a few branches; stems woody; from colony-forming rhizomes
Flower: white, 5-parted; inflorescence a 4"-16" elongated, branched cluster (cyme) with usually less than 25 stalked flowers; blooms June-Aug.
Fruit:smooth, white to yellow berry
Leaf:alternate, stalked, usually near the top of the stem, shiny, smooth, 3 parted, the widely-oval leaflets with a pointed tip
Habitat: full to partial sun; woods edges, openings, prairies
(Glossary)

More Information Natural Communities Herbarium Specimens
All Toxicodendron list Google- Images or Text
Synonyms 
Rhus radicans L. var. rydbergii (Small ex Rydb.) Rehder
Rhus radicans L. var. vulgaris (Michx.) DC.
Rhus rydbergii Small ex Rydb. (pro parte)
Rhus toxicodendron L. var. vulgaris Michx.
Toxicodendron desertorum Lunell
Toxicodendron radicans (L.) Kuntze var. rydbergii (Small ex Rydb.) Erskine

         
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