I am planning to decorate my wedding cake with Alstroemeria. Are these flowers safe to use? The flowers won’t be eaten, but will be in contact with the icing.
The website of National Sustainable Agriculture Information Service has a page of resources on edible flowers, including links to information about toxic plants. Alstroemeria can cause contact dermatitis when handled, and ingesting the plant can cause gastrointestinal problems. See the following information on Alstroemeria from North Carolina State University Extension.
Rather than take any chances, I recommend restricting your decoration choices to
edible flowers. A mixture of calendula, lavender, and violet blossoms, for
example, might be an attractive option. North Carolina State University Extension also has an article on edible flowers.
Iowa State University Extension has useful guidelines on selecting edible flowers.