General poisoning notes:

Hydrangea (Hydrangea macrophylla) is an outdoor ornamental that is grown in the warmer parts of Canada. This plant has poisoned humans after they ingested the flower buds. Sensitive individuals can develop dermatitis after exposure to hydrangea. Older case reports of poisoning of horses and cattle appear in the literature, but no recent reports are available (Apted 1973, Bruynzeel 1986, Fuller and McClintock 1986).

References:

Apted, J. H. 1973. Phytodermatitis from hydrangeas. Arch. Dermatol., 108: 427.

Bruynzeel, D. P. 1986. Allergic contact dermatitis to hydrangea. Contact Dermatitis, 14: 128.

Cooper, M. R., Johnson, A. W. 1984. Poisonous plants in Britain and their effects on animals and man. Her Majesty's Stationery Office, London, England. 305 pp.

Fuller, T. C., McClintock, E. 1986. Poisonous plants of California. Univ. California Press, Berkeley, Calif., USA. 432 pp.

Nomenclature:

Scientific Name: Hydrangea macrophylla (Thunb.) Ser.
 

Vernacular name(s): hydrangea

Scientific family name: Saxifragaceae

Vernacular family name: saxifrage

Go to ITIS*^ca for more taxonomic information on: Hydrangea macrophylla

References:

Agriculture Quebec. 1975. Noms des maladies des plantes du Canada/ Names of plant diseases in Canada. , Quebec City, Que., Canada. 288 pp.

Alex, J. F., Cayouette, R., Mulligan, G. A. 1980. Common and botanical names of weeds in Canada/Noms populaire et scientifiques des plantes nuisibles du Canada. Revised. Agric. Can. Publ., Ottawa, Ont., Canada. 132 pp.

Bailey, L. H., Bailey, E. Z. 1976. Hortus third. Revised. MacMillan, New York, N.Y., USA. 1290 pp.

Scoggan, H. J. 1978, 1979. The flora of Canada. Nat. Mus. Nat. Sci. (Ottawa) Publ. Bot. 7(1)-7(4). 1711 pp.

Van Wijk, H. L. 1911. A dictionary of plant names. Martinus Nijhoff, The Hague, The Netherlands. 1444 pp.

Victorin, M. 1964. Flore Laurentienne. 2nd ed. Univ. Montreal, Montreal, Que., Canada. 952 pp.

Geographic Information

Plant or plant parts used in or around the home.

References:

Bailey, L. H., Bailey, E. Z. 1976. Hortus third. Revised. MacMillan, New York, N.Y., USA. 1290 pp.

Boivin, B. 1966, 1967. Énumération des plantes du Canada. Provencheria 6. Nat. Can. (Que.) 93: 253-274; 371-437; 583-646; 989-1063. 94: 131-157; 471-528; 625-655.

Image or illustration

hydrangea:

Images: images.google.com

Toxic parts:

flower buds
leaves
 

References:

Der Marderosian, A. H., Giller, F. B., Roia, F. C. 1976. Phytochemical and toxicological screening of household ornamental plants potentially toxic to humans. 1. J. Toxicol. Environ. Health, 1: 939-953.

Notes on Toxic plant chemicals:

Hydragin, a cyanogenetic glycoside, is presumed to be responsible for toxicity because it can release hydrocyanic acid upon hydrolysis. Der Marderosian and Roia (1976) administered 3 g of plant extract intraperitoneally, in 10 mL of liquid suspension per 100 g of body weight. All rats died when given extracts from hydrangea flowers and leaves. No mice died when orally fed 100 mg of flower material per 35 g body weight.

Toxic plant chemicals:

hydragin
 

References:

Der Marderosian, A. H., Giller, F. B., Roia, F. C. 1976. Phytochemical and toxicological screening of household ornamental plants potentially toxic to humans. 1. J. Toxicol. Environ. Health, 1: 939-953.

Lampe, K. F., McCann, M. A. 1985. AMA Handbook of poisonous and injurious plants. American Medical Assoc. Chicago, Ill., USA. 432 pp.

Animals/Human Poisoning:

Note: When an animal is listed without additional information, the literature (as of 1993) contained no detailed explanation.

Cattle

General symptoms of poisoning:

abdominal pains
breathing, labored
diarrhea
 

References:

Cooper, M. R., Johnson, A. W. 1984. Poisonous plants in Britain and their effects on animals and man. Her Majesty's Stationery Office, London, England. 305 pp.

Horses

General symptoms of poisoning:

diarrhea
 

Notes on poisoning:

A horse that ingested hydrangea experienced contraction of the abdominal muscles, diarrhea, and stiffness of limbs (Cooper and Johnson 1984).

References:

Cooper, M. R., Johnson, A. W. 1984. Poisonous plants in Britain and their effects on animals and man. Her Majesty's Stationery Office, London, England. 305 pp.

Humans

General symptoms of poisoning:

abdominal pains
coma
diarrhea
erythema
gastroenteritis
lethargy
vomiting
 

Notes on poisoning:

Ingesting hydrangea flower buds has resulted in poisoning (Fuller and McClintock 1986).

References:

Apted, J. H. 1973. Phytodermatitis from hydrangeas. Arch. Dermatol., 108: 427.

Fuller, T. C., McClintock, E. 1986. Poisonous plants of California. Univ. California Press, Berkeley, Calif., USA. 432 pp.