Shell-entangled, bright-hued seaweed,
From what mermaid-haunted bowers
Wert thou cast? did rude waves tear thee
From thy beauteous sister flowers?

Or did glittering star-fish tempt thee?
Did the Nautilus say, Come?
Did they whisper ‘neath the crystal,
Of a fairer, brighter home?

–S.E. Tonkin, “Seaweed” (1866)

Michael Innes’s 1977 mystery novel Honeybath’s Haven sees eccentric artist Edwin Lightfoot drowned in a saline pool of cultivated seaweeds. A pet project of Lady Munden, a fellow inmate of the retirement home in which Lightfoot lived, the pool is thick with great sea tang, whose stems are “as thick as a cable,” and sinewy bull-head kelp. It was this latter plant that proved Lightfoot’s undoing. So ensnared did he become in it, a policeman at the scene noted, that “the body had to be cut out of the stuff.”

Lightfoot’s death (murder?) notwithstanding, the centuries have seen seaweed be more a boon than a bane. Almost all of them are edible and nutritious to boot, with the most toothsome of all being those specimens we often come across on the beach. Nori, sea grapes, kombu, laver, dulse — all have been enjoyed throughout the centuries. Yet for all their usefulness seaweeds retain an aura of mystery. Officially an macro-algae, seaweeds belong to an ungainly and heterogenous group of organisms without taxonomic structure. There might be between one and ten million species, many of which have yet to find their way into scientific literature. At present, only 35,000 or so have been described. Colored either red, brown, or green, they produce neither leaves, fruit, nor roots, setting forth instead fronds, stems, or algae bodies. Half grow in the water; the other half, on land.

People have long attempted to catalogue the edible varieties. A Japanese–Chinese dictionary dating from 934 CE describes 21 different species of edible seaweed. This interest in seaweed taxonomy stemmed from its value as a foodstuff. In Japan, people offered seaweed to the emperor and the nobility as taxes. In small boats and with long-handled hooks, scythes, and rakes, they dredged the ocean floor and rocks for kombu, mozuku, wakame, and other varieties. Their harvest found its way into soups and sushi, puddings and bread. Seaweed was of such importance to the Japanese they often made it the subject of literature. Of a young seaweed gatherer an 8th-century Japanese poet writes that she “will have cut and reaped the fine seaweed, / Bending and yielding” with the waves.

Victorian Englishwomen also reaped seaweed, albeit for reasons all their own. Along the melancholy coastlines of North Devon’s Ilfracombe and Kentish Ramsgate they walked, shod in boy’s boots, tin pails slung over their shoulders in which they carried their harvest, poles in hand to poke and prod the rocks and tidal pools for exotic seaweeds which they would later dry and press into albums. For them seaweed collecting was a gentle exercise, a “resource against weariness, or a light possible occupation during hours of sickness,” as one collector put it. For many it was also a sensual experience. “Enjoy yourself thoroughly as you go,” writer Margaret Gatty wrote in her British Seaweeds of 1872, “never minding a few touches from the last gentle waves as they ripple over at your feet.” Novelist George Eliot found the flora within tidal pools so enchanting she confessed to being “quite in love with sea-weeds.”

Where the middle classes saw a revivifying hobby, the poor saw nourishment. Seaweed was one of those rare foods that depended neither on toil nor the vicissitudes of weather. In season, it arrived on the shores, and did so abundantly. “Poor people need never be hungry when you have the strand,” noted one cookbook author. Medieval Irish monks gathered it for their impoverished parishioners, who ate it with dried fish, potatoes, or turnips. And it made fit fodder for livestock, as well. The minister of the Scottish island of Cumbrae sent his manservant to cut from the rocks at ebb-tide seaweed for his cows, who “neither snuffed nor turned up their noses at it, but relished it and throve upon it.”

While the minister’s cows relished seaweed raw and unseasoned, the minister himself likely took more pains in its preparation. There were numerous ways of preparing seaweed. The people of Iceland washed dulse in fresh water, and sunned it until such time as a white, powdery substance (which is reportedly sweet and tasty) came to cover the whole plant. They then packed the dulse in casks for storage. When removed from storage it was served with fish and butter. If the household was a wealthier one, dulse usually arrived at table boiled in milk and sprinkled with rye flour. The Irish ate dulse between two buttered slices of bread, added it to mashed potatoes, or boiled it with limpets to make an inky stew. The Welsh ate their laver in much the same way: boiled and seasoned and served with something more substantial, bacon or cockles, or sometimes just fried with a dusting of oatmeal.

Seaweed was remarkably versatile. Whatever amount that didn’t make it to tables or larders found use variously as mattress stuffing, roofing material (seaweed is fire resistant), insulation for ice pits, fertilizer, and combustible fuel. Indeed, its versatility extended even to the domain of natural medicine. Physicians in China used seaweed for relieving constipation and healing cysts. For Italians suffering goiter, seaweed was their treatment of choice. And in England, case of scrofula would likely see application of brown algae.

Today our use of seaweed is largely invisible. It thickens puddings and ice cream and is found in everything from wound dressings to dental molds. Seldom is it found in the produce aisle. When it is, it comes at a high price. But if you are lucky enough to live by the sea, now is one of the better times to harvest kelp or Irish moss. Should you find some of the latter, try the following recipe for Irish Moss Jelly from the Liverpool School of Cookery Recipe Book (1900).

Irish Moss Jelly

1/4 oz. Irish moss
1 pint milk or water
Strip of lemon rind
1 oz. sugar

Method: Soak the moss in cold water and wash it well. Put it into a saucepan with the lemon rind and milk or water, simmer very gently for 1/2 hour, add the sugar, and strain into a wet mould. When cold, turn out.