Lots of flowers are very toxic! Foxglove, honeysuckle, snowdrops, daffodils, bluebells, rhodedendron... are all fatally toxic to name a few common garden ones. Hemlock although it is related to parsley...buttercups are very toxic too, there are lots of very pretty but deadly flowers common flowers, I'd stick to dandelions and clover and rose petals and do some serious research first if you plan on feeding foraged stuff...