An Uncommon Beauty
Metedeconck River Banks
Brick, New Jersey USA
Canon Elph 100HS
International Women’s Photography
Wildflowers Of North America
Milkweed is a native perennial herb with milky sap and leaves opposite or whorled, simple and entire; the flowers are in umbels, purple to greenish white; the fruit is a follicle, with numerous seeds, each with a tuft of silky hairs.
As early as the mid 1800s, naturalists observed that birds avoided eating certain butterflies (Monarch) whose larvae fed primarily on milkweed. It was later shown that the feeding larvae accumulated emetic cardiac glycosides which were retained and even concentrated in adult butterflies. Birds eating the butterflies containing these glycosides vomited shortly after ingestion thus learning to avoid certain butterflies.
Dosages of whorled milkweed as low as 0.1 % – 0.5% of the animal’s body weight may cause toxicosis and, possibly, death. Cattle, sheep and horses are most susceptible. Toxicity is not lost when the plant is dried. Therefore, contaminated hay is potentially toxic.
(courtesy of University of Pennsylvania’s Poisonous Plants)