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Apocynum androsaemifolium and cannibum


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Images on this page contributed by:  Ann F. Rhodes, PhD, Director of the Pennsylvania Flora Project

DescriptionPerennial, erect, colony-forming herbs with red stems growing to 4-6 feet.  Apocynum has simple, opposite leaves and small green-white flowers.  The plant contains a white, milky sap.  Fruits are 3-8 inch long double-seeded pods.
Geographic rangeCommonly found in open spaces, along streams, irrigation ditches, and roadsides throughout North America.
Toxic principleToxicity is due to apocynin, which is a resin, and two glycosides: cymarin and apocynein.
ToxicityRarely associated with disease because the texture and taste of the plant is unfavorable and often ignored by livestock.  Toxicity has not been determined.  All parts of the plant are toxic but clinical signs are only seen when new shoots are eaten or when Apocynum is dried and baled with hay.

Clinical signsDiarrhea is a common clinical sign and may be bloody.   Signs of cardiac insufficiency are also seen and these include weakness, cold extremities, bradycardia, and arrhythmias.  Impaction and constipation may occur because of the fibrous nature of the plant.

LesionsLesions are not likely to be seen at necropsy.  Plant material may be found in the stomach contents.

TreatmentSymptomatic treatment with oral activated charcoal should provide relief of clinical signs.
PreventionHay should be examined before feeding and discarded if it is found to contain Apocynum is found. 
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Copyright 2002

University of Pennsylvania
Created by:    Alexander Chan (2003), Daphne Downs (2002), Chris Tsai (2001), Brett Begley (2000), Janet Triplett (1997)
Faculty Advisor:  Dr. Robert Poppenga