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Wednesday - August 15, 2012

From: Los Angeles, CA
Region: California
Topic: Poisonous Plants, Trees
Title: Is Lemon Cypress toxic?
Answered by: Nan Hampton


Is the Lemon Cypress toxic?


Lemon cypress is a cultivar of Cupressus macrocarpa (Monterey cypress), a native of California.  It does not appear on any of the following toxic plant databases:

Poisonous Plants of North Carolina

Cornell University's Plants Poisonous to Livestock and Other Animals

Canadian Poisonous Plants Information System

University of Pennsylvania's Poisonous Plants

California Poison Control System

However, I did find some reports saying the Cupressus macrocarpa caused spontaneous abortions in cattle in New Zealand.  The FDA Poisonous Plant Database has a report of poisoning of cattle in New Zealand and in Australia: 

MacDonald, J. (1956) Macrocarpa poisoning. New Zealand Veterinary Journal 4:30. 

Sloss, V. and J. W. Brady (1983).  Abnormal births in cattle following ingestion of Cupressus macrocarpa foliage.  Australian Veterinary Journal 60 (7):223.

USDA ARS Poisonous Plant Research database reports a paper stating that the consumption by cattle of Monterey cypress causes abortions.  [Lee, S. T. et al.  (2003)  Development of Enzyme-Linked Immunosorbent Assays for Isocupressic Acid and Serum Metabolites of Isocupresssic Acid.  Journal of Agricultural and Food Chemistry.]

It does appear that Cupressus macrocarpa, if eaten, poses a threat to pregnant cattle; but I could find no indication that it is toxic to humans.  It would seem prudent, however, NOT to consume it.




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