The Brussels sprout is one of the youngest of the world's major vegetables, and unlike the almond or the plum it is neither a separate species nor an ancient domestication: it is a single cultivar group of Brassica oleracea, the wild cabbage of the European sea cliffs that is also the ancestor of the kale, the cabbage, the broccoli, the cauliflower, and the kohlrabi (see those entries for the wild cole's long story). What distinguishes the sprout from its many cousins is the way it grows. Where the cabbage gathers a single great head at ground level, the Brussels sprout sends up a tall, thick stem along which, in the axil of each leaf, a small tight head forms, so that one plant bears dozens of miniature cabbages spiralling up the stalk. The botanical name records exactly this habit: var. gemmifera, 'bud-bearing', from the Latin gemma, a bud or gem.

The sprouting cole was developed in the southern Low Countries, in the duchy of Brabant around Brussels, and the city gave the vegetable its name in nearly every European language. Cultivation in the region is sometimes traced to the thirteenth century, but the first clear written descriptions date from the later sixteenth century, and the modern form, with its dense, even buttons closely set up a long stem, was fixed in the market gardens around Brussels by the eighteenth century. From that single Brabant homeland the plant spread, slowly and recently, across the cool, damp lands of Northern Europe, where it found the long, cold growing season it needs; the sprout is hardy to hard frost, and indeed a touch of frost is held to sweeten it, which made it the great fresh green vegetable of the Northern European winter.

The sprout's character, and its long reputation as the most divisive vegetable on the table, rests on a group of sulphur compounds, the glucosinolates sinigrin and progoitrin, which give it both its cabbagey pungency and, in the older varieties, a marked bitterness. A significant share of people carry a bitter-taste receptor that makes those compounds taste intensely, even unpleasantly, sharp. The transformation of the sprout's fortunes in recent decades owes much to plant breeding: in the 1990s Dutch researchers identified the specific bitter compounds and crossed older, milder varieties back in to breed them down, producing the sweeter, more tender sprout of the modern supermarket and rescuing the vegetable from the overcooked, sulphurous ill repute of the mid-twentieth century. Modern cultivar work has also given the red-purple Brussels sprout (such as 'Rubine') and, in 2010, the kalette or flower sprout, a deliberate cross of Brussels sprout and kale.

The Brussels sprout's journey is short, recent, and almost entirely Northern European, the radiation of a single Brabant vegetable across the cool lands around it. From its home around Brussels the sprout spread first through the rest of the Low Countries, into the Netherlands, where it became a winter staple mashed through the potato in the dish stamppot, and into the kitchen gardens of northern France, where it took the name chou de Bruxelles and was dressed in cream or sautéed with lardons in the manner of the French table. It moved east into the German lands, where the buds, thought to resemble little roses, were named Rosenkohl, the 'rose cabbage', and stewed with chestnuts for the winter and the Christmas table.

The most consequential crossing was the shortest. The sprout reached Britain across the Channel in the early nineteenth century, and no nation took it to heart, or to argument, more completely. The British made the Brussels sprout the indispensable green of the Christmas dinner, boiled or, latterly, roasted and tossed with bacon and chestnuts, and folded the leftovers the next day into bubble and squeak; today Britain grows and eats the sprout in quantities out of all proportion to the rest of the world, the supermarkets shifting many thousands of tonnes in the single week before Christmas.

Across the Atlantic the sprout travelled with French settlers, who are said to have carried the chou de Bruxelles to Louisiana around 1800. It remained a minor crop until the twentieth century, when commercial cultivation took hold in the cool, fog-bound coastal valleys of central California, around Santa Cruz and the Monterey Bay, a microclimate so suited to the plant that the district became the heart of the American sprout industry. There, at the turn of the present century, the Brussels sprout underwent the most dramatic rehabilitation of any vegetable of our age: American chefs, led by the restaurant kitchens of New York and California, began to roast and to deep-fry the sprout rather than boil it, dressing it with bacon, balsamic, chilli, and fish sauce, and turned the most hated vegetable of the twentieth-century table into one of the most fashionable of the twenty-first.

The Brussels sprout remains, above all, the vegetable of the Northern European winter and of Christmas. Britain is its greatest devotee, growing and consuming it on a scale no other country approaches and treating it as the non-negotiable green of the Christmas dinner, a role that sustains an annual national debate between those who love the sprout and those who endure it. Belgium, the Netherlands, France, and Germany keep it as a everyday cold-weather vegetable, mashed into stoemp and stamppot, creamed, or stewed with chestnuts as Rosenkohl. Across these countries the sprout is harvested from autumn through the frosts, sold both loose and, increasingly, still attached to its tall, dramatic stalk.

The vegetable's standing has been transformed twice over in living memory. First by the plant breeders, whose work from the 1990s onward bred out the harsh bitterness of the older varieties and gave the world a sweeter, milder sprout; and second by the cooks, whose discovery that high, dry heat (roasting and frying, rather than the long boiling that had defined the sprout for generations) renders the vegetable nutty, crisp, and caramelised, banishing the grey, sulphurous mush of memory. The American restaurant fashion for crisp-fried and roasted sprouts, dressed boldly with bacon, balsamic, maple, chilli, and fish sauce, spread around the world in the 2010s and carried the sprout into a global popularity it had never before enjoyed.

Nutritionally the sprout is a notable source of vitamin C and vitamin K and of the glucosinolates whose breakdown products, including sulforaphane, are of interest for their possible protective effects, the same family of sulphur compounds that gives the vegetable its character. California remains the centre of cultivation in the United States; Britain, the Netherlands, and Germany lead in Europe; and the red sprout and the kale-cross kalette have added colour and novelty to a vegetable that, for all its recent fashionability, remains rooted in the market gardens of the city whose name it carries.