Many of the best edible wild plants grow very close to the coast, which, of course, we have rather a lot of in the UK. These fall into three sub-categories. The first are the green seaweeds, which are actually primitive plants (unlike the brown and red seaweeds). The second are the saltmarsh plants that grow in areas immediately above the high tide line, or are partially submerged for short periods of time.
The most famous of these is marsh samphire, which is actually a whole genus of plants (Salicornia) rather than a single species, including both annual and perennial species. Their traditional name was “Glassworts”, and long before people started eating them, they were burned to extract the silicates from them, which were then used in glassmaking processes. The name “samphire” rightfully belongs to a completely different plant, which now has to be called “Rock Samphire” to distinguish it from Marsh Samphire. Marsh Samphire was first collected as food as an adulterant to the more highly-regarded Rock Samphire – the true “Samphire”
Another saltmarsh plant, this one can be found in wild abundance. Where it grows – which is all around the southern coastlines of Britain and now becoming established ever further north, it often dominates utterly. It is naturally very salty, and tender, and is best served raw as a garnish to fish dishes. It can also be steamed for a short period of time, but not for too long or it will start to turn bitter.
The third sub-category of coastal plant are those that grow in areas close to the coast, but not actually close enough to ever get wet. These plants are salt-tolerant and usually wind-tolerant. The absolute best of these is a species brought to the UK as a food plant by the Romans, but which fell out of favour in the 19th century after the development of modern forms of celery. It can be grown inland, and even still survives in the wild in some places it was once grown (such as monastic ruins), but it only thrives near the coast. Alexanders (or Rock Parsley of Alexandria) is also very useful because it is one of the few wild greens that is available right through the winter – although it is at its best in May.
This plant is the wild ancestor of beetroot, sugarbeet and chard, which should tell you all you need to know about its relevance to a forager. Here shown growing by the marina on Brighton beach. Sea Beet is very common all around the coastline of Britain.