This salad contains two types of seaweeds: sea lettuce (ulva spec.) and bladder wrack (Fucus vesiculosus L.), and two types of sea vegetable: sea rocket (Cakile maritima) and rock samphire (Crithmum maritimum). It can be hard to tell apart different types of seaweeds but luckily there are no poisonous ones. When you harvest them just make sure you pick them from a clean environment. The two types of seaweeds we picked are relatively easy to recognise. While determining the exact type of sea lettuce requires a microscope or even DNA research, for consumption purposes you only have be able to determine