Chamomile is another flower that can be infused into a tea and taken to enhance sleep – reportedly because it reduces stress. Chamomile is a plant, much like a Daisy, and includes several different sub-species (wild, yellow, etc) – and they all act basically the same. Chamomile Tea is commonly available, and is taken to calm and relax as well as promote sleep. You’ll often find Chamomile mixed in with other “relaxation inducing” flowers and herbs in that tea.
This is probably the stuff your grandmother would recommend for insomnia.
Care should be taken when you take Chamomile – it can cause uterine contractions that may lead to miscarriage. The US Department of Health has advised pregnant women and nursing mothers to avoid it altogether, but it’s generally considered safe for everyone else.