Borage (Borago officinalis) and daylily (Hemerocallis spp.) flowers are diuretics, and sweet woodruff (Galium odoratum) can have blood-thinning effects. The flowers of linden trees (Tilia spp.) are reportedly "safe in small amounts", but heavy consumption can cause heart damage. Marigolds (Tagetes spp.) can be harmful in large amounts, and only certain species have an appealing flavor.[1]