Chapter 1 — The Bulb Itself

"There are around 500 species in the genus Allium, a group of plants in the lily family that are native to northern temperate regions. About 20 are important human foods, and a handful have been prized for thousands of years." — Harold McGee, On Food and Cooking: The Science and Lore of the Kitchen (2004)

T ake a head of garlic in the hand and it is at once the most familiar object in the kitchen and one of the least examined. We buy it, we crush it, we sweep the skins into the bin, and in all that easy handling almost no one stops to ask what, botanically, they are holding — which is a pity, because the answer is stranger than the object's ordinariness lets on. A head of garlic is not a root, though it grows underground; it is not a seed, though it is planted; it is not, properly speaking, a single thing at all. It is a colony of storage organs, a plant that has abolished its own sex life, and a leaf that has learned to become a larder. Before this book can adore garlic, or trace it, or cook it, it owes the bulb the courtesy of understanding what it actually is. So the compendium begins, as it always prefers to, with the specimen on the table and the knife laid down beside it.

A Head, and Its Cloves

The whole object the greengrocer sells is the head, or bulb — in the trade sometimes a "knob," in the older books a "root," which it is not. Strip away its papery outer wrapping — itself the dried remains of the plant's outer leaf-sheaths, not a rind grown for the purpose — and the head resolves into a ring, or several nested rings, of separate segments packed around a common centre. Each segment is a clove, and the clove is the unit that matters, for it is the clove and not the head that the plant treats as an individual. A head of ordinary garlic holds anywhere from half a dozen to twenty cloves, the number a fair guide to its kind — a handful of large ones to a hardneck, a crowd of small ones to a softneck — and they are arranged with a geometry that is not decorative but structural: they are all attached, at their lower ends, to the same small woody disc at the base of the bulb.

That disc is the basal plate, and it repays a moment's attention because it is the secret of the whole architecture. The basal plate is not a root and not a mere platform; it is a compressed stem — the plant's true stem, telescoped into a hard flat button no thicker than a coin. From its underside descend the roots, the pale cluster of threads that anchor the plant and draw its water, and which are the one part of the bulb that no cuisine bothers to eat. From its upper surface arise the cloves. Everything green the plant will ever make, and everything the plant has stored to make it with, hangs off this single modified stem. To understand a bulb is to understand that its "up" and "down" are the residue of a plant that has folded almost entirely into itself.

Now the clove itself, cut lengthwise. Inside its own tight jacket of skin — a dry, close-fitting tunic — the clove is mostly a single swollen, curved mass of pale flesh, and that flesh is a storage leaf: one leaf, thickened and gorged with sugars and reserves, wrapped protectively around what it exists to protect. Tucked along the clove's inner curve, if the clove is at all mature, is a slender pale-to-green sprout — the germ, the folded shoot of the next plant, waiting. Cooks who dislike a faint bitterness in raw garlic sometimes lift this green sprout out and discard it, and they are, without knowing it, removing the one part of the clove that is unambiguously alive and forward-looking: the embryo of a whole new garlic plant, provisioned by the storage leaf that surrounds it exactly as a seed is provisioned by its own reserves. The head, then, is a bundle of these — a cluster of complete plants-in-waiting, each sealed in its skin, each stocked for the journey, all sharing one compressed ancestral stem.

Field Note — The Clove

Hold one clove up to the light and consider what it is not. It is not a seed, though it behaves like one, storing food around a dormant shoot and waiting for the season to turn. It is not a fruit, for nothing was fertilised to make it. It is, in the plainest botanical terms, a bulbil: a swollen bud, an offset, a piece of the parent plant that has been packed with reserves and given its own skin so that it can be broken off and sent into the ground to grow. Everything it needs is already inside it. The thick, translucent flesh is a single leaf that has given up the ambition of ever being green in order to become a pantry; the pale spear along its spine is the leaf, and the stem, and the future plant, all present in miniature and merely paused.

The consequence is quietly astonishing. When a gardener plants a clove, no germination in the ordinary sense takes place — no seed splits, no two cells combine. The clove simply resumes a growth that was interrupted, unfolding its waiting shoot upward and pushing new roots down from the same basal scar, and in a season it builds, from that one leaf's worth of stored sugar, a whole new head of a dozen more cloves. Each of those is genetically identical to the clove that was planted, and to the plant that bore it, and to the plant before that, back along a line that in some cultivated strains has not passed through a seed in thousands of years. The clove is the plant's answer to a problem it can no longer solve the usual way — a way of making more garlic without ever making a child.

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<g font-family="'Liberation Sans','DejaVu Sans',sans-serif" font-size="11" letter-spacing="1.5" fill="#43331f"> <g stroke="#6f5a40" stroke-width="0.5" fill="none"> <path d="M236 118 L236 92 L360 92"/> <path d="M262 236 L312 236 L312 210 L360 210"/> <path d="M236 412 L200 434 L120 434"/> <path d="M236 470 L236 500 L120 500"/> <path d="M496 220 L512 202"/> <path d="M500 300 L516 300"/> </g> <text x="364" y="95">SPROUT (green shoot)</text> <text x="364" y="213">WRAPPER LEAVES</text> <text x="116" y="437" text-anchor="end">BASAL PLATE</text> <text x="116" y="503" text-anchor="end">ROOTS</text> <text x="608" y="199" text-anchor="end">PAPERY TUNIC</text> <text x="608" y="303" text-anchor="end">SINGLE CLOVE</text> </g>

<text x="320" y="592" text-anchor="middle" font-family="'Liberation Sans','DejaVu Sans',sans-serif" font-size="13" letter-spacing="4" fill="#43331f">THE ANATOMY OF THE BULB</text> </svg>

<figcaption><em>Plate 1. The anatomy of the bulb (Allium sativum): the whole head in cross-section and a single clove drawn exploded — basal plate, roots, papery tunics, the storage leaf, and the waiting sprout.</em></figcaption> </figure>

The Logic of a Bulb

It is worth asking why a plant should go to the trouble of becoming a bulb at all, because the answer is stamped all over garlic's character. A bulb is a survival device — a way of packing an entire plant, leaves and stem and next year's shoot, into a dense underground parcel of stored food and then shutting the whole thing down. Plants that live by this trick, the botanist's geophytes, are overwhelmingly the plants of hard, seasonal climates, of places where the year swings between a spell fit for growing and a spell fit only for hiding: the baking, rainless summers and hard-frozen winters of the Central Asian uplands where garlic began. Faced with such a year, garlic's strategy is to do all its living in the brief kind window, pour the surplus into a bulb, and then vanish underground as a dormant larder through the killing heat or cold, ready to erupt the moment the season turns. Everything peculiar about the plant follows from this. The clove keeps for months because it was built to keep, through exactly such a dormancy. The whole head is a food-store first and a plant second. And even the sterility makes a kind of sense: a plant that can weather any year by simply withdrawing into its bulb and re-emerging, identical, has less pressing need of the endless genetic reshuffling that seed exists to provide. The bulb is not merely where garlic keeps itself; it is garlic's entire answer to living in a place that is only sometimes survivable.

The Head Above the Ground

So far the plant has been all bulb, which is how the kitchen meets it; but the gardener knows garlic chiefly as a green thing, and its growing form repays a look. Above the buried head garlic throws up not a branching stalk but a fan of long, flat, folded leaves, blue-green and faintly waxy, each one solid rather than hollow — the readiest field mark that separates garlic from the round, tubular-leaved onion. What appears to be a stem carrying those leaves is not one. It is a pseudostem, a false stem built from the tightly rolled, sheathing bases of the leaves themselves wound around one another, exactly as in a leek; the plant's true stem is still the little compressed basal plate hidden below in the bulb. Each leaf, as it emerges, runs down to a clove in the head, so that the green fan above and the clustered cloves below are a single continuous plant — the leaves feeding the bulb through the season, the bulb the swollen bank into which those leaves pour their surplus before they yellow, die back, and let the whole green apparatus vanish for the year. To pull a head in early summer, before it has dried, is to lift this entire living thing intact: fan, false stem, and the fattening cluster all at once.

Hardneck, Softneck, and the Scape

Not all garlic is built to quite the same plan, and the first great division a grower learns is between the two subspecies, the hardneck and the softneck. The distinction is easy to see once pointed out, and it governs almost everything practical about the plant: how it tastes, how long it keeps, where it will grow, and whether it can be plaited into the braid that hangs in the farmhouse kitchen.

A hardneck garlic — the botanists' Allium sativum var. ophioscorodon, from the Greek for "serpent garlic" — does something the softnecks have lost the habit of: it tries to flower. In early summer it sends up from the centre of the bulb a firm, woody flowering stalk, and this stalk, the scape, is one of the small marvels of the garden. It rises, then loops and coils on itself in an elegant curl — a rocambole will often throw a double loop where a porcelain makes a single tall arc — before straightening, and it is topped not by an ordinary flower head but by a papery hood, the spathe, that splits to reveal a cluster of tiny aerial bulblets — bulbils, or topsets — mixed with a few usually sterile blooms. Growers generally cut the scape off while it is young and tender, just as it makes its first curl, both because removing it drives the plant's energy back down into the bulb, making for larger cloves, and because the scape is itself a fine vegetable, mild and green and faintly garlicky, good stir-fried or made into a pesto. The hardneck that keeps its scape produces a bulb with a hard central stalk running through it — the neck that gives the subspecies its name — and a single tidy ring of a few large, easily peeled cloves around that stalk. Hardnecks tend to the cold-hardy and the complex-flavoured, and they are the choice of the northern grower and the connoisseur; their weakness is that they do not store especially long.

A softneck garlic — var. sativum — has, in effect, given up on flowering altogether. It throws no woody scape, so its neck stays soft and pliable as it dries, which is precisely why softneck is the garlic of the braid: only a soft neck can be plaited. Freed from the business of making a stalk, the softneck packs its bulb with more cloves, arranged in several overlapping layers rather than a single ring, the outer ones large and the inner ones small and fiddly to peel. It stores for many months, it is milder and less various on the tongue, and it thrives in warmer climates nearer the equator. It is, overwhelmingly, the garlic of commerce — the anonymous white head in the supermarket net is almost always a softneck, chosen for exactly the virtues that make it dull to the enthusiast and convenient to the grocer: high yield, long life, an even temper.

The Cultivars, and What Each Is For

The two subspecies are only the top of a finer sorting. A grower, or the curator of a seed collection, divides cultivated garlic into about ten horticultural groups, and the division is not merely folklore or marketing: when Gayle Volk and her colleagues at the United States Department of Agriculture's plant-preservation centre at Fort Collins took DNA fingerprints of some two hundred and eleven garlic accessions in the early 2000s, the plants sorted themselves into just such a set of distinct types, confirming with molecular markers what a century of growers had worked out by eye. Two of the groups are the softnecks — the artichoke garlics, the many-cloved workhorses of the supermarket, and the pale, tight silverskins, the longest-keeping of all and the classic garlic of the braid. The rest are hardnecks or near-hardnecks, and among them the enthusiast learns to tell the porcelain garlics, with their few enormous cloves under a smooth, bone-white wrapper and their reputation for cold-hardy vigour; the rocamboles, richest and most complex on the tongue and cursed with a short shelf life; and the three purple-stripe groups — standard, marbled, and glazed — streaked with violet and reckoned by many cooks the finest for roasting. The clove-counts alone tell much of the story: a porcelain head yields only four to six great cloves and a rocambole eight to a dozen, handsome and easy to peel and quick to be spent, while a silverskin or an artichoke packs fifteen or twenty smaller ones in overlapping layers and holds them sound for the better part of a year. A handful of further groups sit awkwardly across the neat hardneck line, bolting weakly or late: the early, vigorous Asiatic and turban garlics, and the colourful creole sorts of warm country, whose in-between habit is a standing reminder that the tidy two-subspecies scheme is a convenience the plant does not always honour.

One of these groups carries a quiet distinction. The same Fort Collins fingerprinting found the purple-stripe garlics sitting closest of all to the genetic root of the species — the basal group, in the language of the phylogeneticists, from which the others appear to have diverged. The violet-streaked clove a modern cook reaches for on looks alone is, on the evidence of its DNA, the nearest thing on the market to the ancestral garlic that first came down out of the mountains of Asia; the porcelains and silverskins and artichokes are its more travelled, more heavily selected descendants. The whole tidy catalogue of named types is, in the end, the record of a single wild plant scattered by human hands across every climate on earth and kept, in each place, as the clone that grew best there.

That local keeping is why the map of garlic's types follows the map of climate so closely. Carried out of Asia as living cloves along the trade roads, garlic could not adapt the way a seed crop does, by throwing up fresh combinations each generation; it could only be sorted, the grower in each place saving the clones that best weathered the local winter and summer and discarding the rest. Over centuries that patient sorting drove the great division the kitchen still lives by — the cold-hardy, scape-throwing hardnecks holding the north, the milder, longer-keeping softnecks spreading through the warm south — achieved not by the plant changing itself but by people choosing, field after field, which unchanging clone deserved to be planted again.

<figure> <svg xmlns="http://www.w3.org/2000/svg" width="100%" viewBox="0 0 640 440" role="img"> <title>The Allium Kin and the Cultivars — a botanical tree</title> <g fill="none" stroke="#43331f" stroke-width="1"> <rect x="10" y="10" width="620" height="420"/> <rect x="14" y="14" width="612" height="412" stroke-width="0.6"/> </g> <g stroke="#6d5577" stroke-width="1.2" fill="none"> <path d="M14 30 L14 14 L30 14"/> <path d="M626 410 L626 426 L610 426"/> </g> <g font-family="'Liberation Sans','DejaVu Sans',sans-serif" fill="#43331f"> <text x="320" y="40" text-anchor="middle" font-size="15" letter-spacing="4">THE ALLIUM KIN & THE CULTIVARS</text> <text x="320" y="56" text-anchor="middle" font-size="8.5" letter-spacing="2" fill="#6f5a40">GENUS ALLIUM · FAMILY AMARYLLIDACEAE</text> </g>  <g fill="none" stroke="#6f5a40" stroke-width="0.9" stroke-linecap="round"> <path d="M78 222 H110 M110 100 V312 M110 100 H146 M110 140 H146 M110 190 H146 M110 222 H146 M110 272 H146 M110 312 H146"/> <path 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-11 -6 -13 Z M442 277 v -3 M439 281 v 9 M445 281 v 9"/> </g>  <g font-family="'Liberation Sans','DejaVu Sans',sans-serif" text-anchor="middle"> <text x="70" y="210" font-size="11" letter-spacing="2" fill="#43331f">ALLIUM</text> <text x="70" y="236" font-size="6.5" letter-spacing="1" fill="#6f5a40">the genus</text> </g>  <g font-family="'Liberation Sans','DejaVu Sans',sans-serif" fill="#43331f"> <text x="150" y="103" font-size="10" letter-spacing="1">ONION</text> <text x="150" y="113" font-size="6.5" font-style="italic" fill="#6f5a40">A. cepa</text> <text x="150" y="143" font-size="10" letter-spacing="1">LEEK</text> <text x="150" y="153" font-size="6.5" font-style="italic" fill="#6f5a40">A. ampeloprasum</text> <text x="172" y="165" font-size="7.5" letter-spacing="0.5" fill="#6d5577">ELEPHANT ‘GARLIC’</text> <text x="172" y="175" font-size="6.5" font-style="italic" fill="#6f5a40">a leek, not a garlic</text> <text x="150" y="193" font-size="10" letter-spacing="1">SHALLOT</text> <text x="150" y="203" font-size="6.5" font-style="italic" fill="#6f5a40">A. cepa Aggregatum</text> <text x="150" y="225" font-size="11" letter-spacing="1.5">GARLIC</text> <text x="150" y="235" font-size="6.5" font-style="italic" fill="#6f5a40">A. sativum</text> <text x="150" y="275" font-size="10" letter-spacing="1">CHIVE</text> <text x="150" y="285" font-size="6.5" font-style="italic" fill="#6f5a40">A. schoenoprasum</text> <text x="150" y="315" font-size="10" letter-spacing="1">RAMP</text> <text x="150" y="325" font-size="6.5" font-style="italic" fill="#6f5a40">A. tricoccum</text> </g>  <g font-family="'Liberation Sans','DejaVu Sans',sans-serif" fill="#43331f"> <text x="304" y="182" font-size="10" letter-spacing="1">HARDNECK</text> <text x="304" y="193" font-size="6.5" font-style="italic" fill="#6f5a40">Ophioscorodon · bolting, scapes</text> <text x="304" y="259" font-size="10" letter-spacing="1">SOFTNECK</text> <text x="304" y="270" font-size="6.5" font-style="italic" fill="#6f5a40">Sativum · no scape, braids well</text> <text x="458" y="153" font-size="8.5" letter-spacing="0.5">ROCAMBOLE</text> <text x="458" y="163" font-size="6" fill="#6f5a40">rich, easy to peel</text> <text x="458" y="188" font-size="8.5" letter-spacing="0.5">PORCELAIN</text> <text x="458" y="198" font-size="6" fill="#6f5a40">few large cloves, hardy</text> <text x="458" y="223" font-size="8.5" letter-spacing="0.5">PURPLE STRIPE</text> <text x="458" y="233" font-size="6" fill="#6f5a40">the ancestral group</text> <text x="458" y="251" font-size="8.5" letter-spacing="0.5">ARTICHOKE</text> <text x="458" y="261" font-size="6" fill="#6f5a40">many cloves, stores long</text> <text x="458" y="287" font-size="8.5" letter-spacing="0.5">SILVERSKIN</text> <text x="458" y="297" font-size="6" fill="#6f5a40">the braiding garlic</text> </g>  <line x1="150" y1="400" x2="490" y2="400" stroke="#a9906c" stroke-width="0.6"/> <text x="320" y="420" text-anchor="middle" font-size="8" letter-spacing="1" fill="#43331f" font-family="'Liberation Sans','DejaVu Sans',sans-serif">ONE GENUS, MANY KIN — AND MANY GARLICS OF A SINGLE SPECIES</text> </svg>

<figcaption><em>Plate 2. The kin and the cultivars: on one branch the wider genus — onion, leek, shallot, chive, ramp — with elephant 'garlic' flagged as a leek in disguise; on the other, garlic's own domesticated groups, the hardnecks (porcelain, rocambole, purple stripe) set against the softnecks (artichoke, silverskin).</em></figcaption> </figure>

The Plant's Year

A clove is not sown like a seed and does not behave like one, and the garlic year is worth following once, because it explains where and when the crop is grown. The gardener pushes cloves into the ground in autumn, point upward, and each clove at once sends roots down and then sits out the winter, scarcely growing above the soil. That winter is not endured but required. Garlic needs a spell of cold — something on the order of six to eight weeks near or below ten degrees Celsius — to trigger the change from a single storage clove into a whole new divided head, a cold-priming that plant scientists call vernalization; a clove denied its winter will often refuse to divide at all and swell instead into one undivided ball, a grower's "round," perfectly good to eat but a single fat clove where a head should be. Having been chilled, the plant waits on a second signal, which is light. As the days lengthen through spring the leaves read the growing hours and pass the word down to the base of the plant to stop making leaves and start making cloves; long days and rising warmth drive the bulbing, and the hardnecks throw their scape. By midsummer the leaves yellow and topple, the bulb is made, and the crop is lifted — and then comes the last and most easily botched step, the curing, in which the heads are dried in warm, moving air for some weeks until the outer wrappers set to paper and the neck seals, which is the whole secret of a garlic that keeps until spring rather than sprouting or rotting by autumn. Autumn in, summer out, a winter's cold in the middle: the rhythm is why the finest hardnecks belong to growers with real winters, and why the plant is, for all its Mediterranean and Asian reputation, at heart a creature of the cold-then-lengthening year.

Keeping the Clove

A well-cured head is built to last, but only if it is kept in the right kind of cool, and here most kitchens get garlic exactly wrong. The cured bulb is dormant, its sprout paused; what breaks that dormancy and wakes the sprout is temperature, and — against every instinct — the danger is not warmth but the moderate chill of the refrigerator. Garlic loses its dormancy and sprouts fastest at intermediate temperatures, somewhere in the range of five to eighteen degrees Celsius, which is exactly where a domestic fridge, at around four degrees and clammy with humidity, sits close to the sprouting-friendly edge; a head kept there tends to turn rubbery, grow mould, and push out green shoots the sooner. The commercial trade avoids that middle band from both sides, holding garlic either just above freezing, at minus one to zero degrees and low humidity, where it will keep sound for the better part of a year, or else cool and dry at ordinary larder warmth. For the cook the rule is simply put: keep garlic like an onion, not like a lettuce — somewhere cool, dark, dry and airy, in mesh or paper, and never sealed in the cold damp of the salad drawer. A head that does sprout is not spoilt, only ageing: the green shoot lives off the clove's reserves and turns it gradually soft, hollow and faintly bitter, the same acridity that haunts the germ the cooks of this chapter lift out — and it is this slow bittering, as much as any rot, that finally ends a bulb's usefulness.

The Bulb That Forgot the Seed

The scape's cluster of sterile flowers is the visible sign of a deeper peculiarity, and it is the one fact about garlic that most surprises people when they first meet it: cultivated garlic is, for all practical purposes, sterile. It flowers rarely and reluctantly, and when it does the flowers commonly wither without setting viable seed, their energy diverted into those little aerial bulbils instead. The garlic in the world's kitchens does not, and largely cannot, reproduce the way a bean or a tomato does, by the meeting of pollen and ovule and the making of a seed. It reproduces only by cloning itself — by the division of the head into cloves, each of which is a piece of the parent, and by those bulbils, which are simply smaller pieces of the same.

This is the result of a long domestication that traded sex for reliability. Somewhere in the deep past, growers began selecting garlic for bigger bulbs, more cloves, and dependable flavour, propagating always from the best heads by replanting their cloves; and generation upon generation of that clonal selection gradually let the machinery of seed-making fall into disuse, until the crop we grow today is a collection of ancient clones, some of them perhaps carried unbroken across millennia and continents without once passing through a seed. It is a strange kind of immortality and a real vulnerability at once: a clone cannot shuffle its inheritance to meet a new disease, and the loss of fertility long denied breeders the ordinary tool of crossing one strain with another. Only in recent decades have researchers, working with wild and semi-wild material from garlic's homeland, coaxed some cultivated lines back into producing true seed — reopening, deliberately, a door the plant had let quietly close.[^1]

That reopening has a name and a place attached to it. In the 1980s the Japanese researcher Takeomi Etoh, working with garlic collected in its Central Asian homeland, found what centuries of European and East Asian cultivation had bred out: clones that were still male-fertile, able to set true seed if the crowding bundle of bulbils was cut from the flower head to let the blooms develop. His first reports could point to a single fertile clone; as more Central Asian material was screened the count climbed — to twenty-seven fertile clones in a later American survey — and seed came in a flood where there had been none, first thousands, then tens of thousands, and in time more than a million true garlic seeds raised from a plant the textbooks had flatly called sterile. The point is not a botanical curiosity. A crop that can only copy itself cannot be bred in the ordinary way; it cannot be crossed to marry one strain's flavour to another's resistance to disease, and it carries its accumulated viruses down the generations in the very cloves from which it is replanted. Restoring true seed hands the garlic breeder, for the first time, the plain tool that the wheat and the tomato breeder have always had. Seed-grown garlic remains, for now, a matter of the trial plot and not the greengrocer — the clove in the reader's kitchen is still a clone of a clone of an ancient clone — but the plant's long sexual amnesia has, after perhaps thousands of years, at last begun to lift.

It lifts, moreover, on a plant grown at a scale that makes its sterility all the more extraordinary. The world raises on the order of twenty-nine million tonnes of garlic in a year, very nearly the whole of it propagated the old way, clove by clove by human hand; and of that global harvest a single country, China, grows close to three-quarters — better than twenty-one million tonnes against a distant second, India, nearer three — so that the anonymous white head in a European or American string bag has, more likely than not, been split from a Chinese field. A plant that gave up sex, carried out of one mountainous corner of Asia by cloning alone, now blankets the planet in tonnages that would flatter a grain.

In its sterility garlic keeps company, at least, with a small and distinguished club. A handful of the crops humanity leans on most have been bred, like garlic, into seedlessness and are carried forward only by cloning: the banana, whose every Cavendish is a cutting of a single plant; saffron, a sterile triploid crocus that has not set seed in all its centuries of use; and several of the yams and taros of the tropics. Each has traded the genetic reshuffling of sex for the dependable sameness of the copy, and each now faces the same quiet peril — that a clone, however vast its acreage, meets every new disease with precisely the inheritance the last plant had and no other. The banana growers, watching a single fungus march through their one variety across the world, know the danger intimately; garlic's recovered seed is, in that light, an insurance they can only envy.

A Homeland, and a Missing Ancestor

Where that homeland lies is reasonably clear in outline and pleasantly disputed in detail. Garlic is a plant of Central Asia — of the mountains and steppes running from western China through the Tien Shan and across Kazakhstan, Kyrgyzstan and Uzbekistan — and it was from somewhere in that region that it was first taken into cultivation and then carried outward, west into Mesopotamia and the Mediterranean and east into China, in the long prehistory of trade. The identity of its precise wild ancestor is the honest gap. For much of the twentieth century the wild species Allium longicuspis was named as the progenitor, and the reader will still find it given as such; but more recent scholarship has argued that A. longicuspis may itself be little more than feral cultivated garlic, and that the true wild parent — perhaps a still-living Central Asian population, perhaps a relative such as the Turkish A. tuncelianum — has not been settled beyond argument. It is exactly the sort of question that garlic's own sterility makes hard to answer, for a plant that will not cross with its relatives will not easily submit to the breeding tests by which such ancestries are usually traced. The compendium is content to leave it where the evidence leaves it: Central Asian, ancient, and not yet pinned to a single wild name.

Two independent lines of evidence at least agree on the cradle. The old principle associated with the botanist Nikolai Vavilov — that a crop is most various, and most nearly wild, at its centre of origin — points squarely at Central Asia, for it was there, and only there, that the fertile, seed-setting clones still survived when the rest of the world's garlic had forgotten the trick. The DNA agrees from the other end: the purple-stripe garlics that the fingerprinting placed nearest the root of the cultivated species are themselves Central Asian in type, the least-travelled branch of the whole family. The homeland, then, is not seriously in doubt. It is only the single wild individual at the very base of the pedigree that has slipped the net — and it may be that in a plant so long and so thoroughly cloned, the question of a lone ancestor has no clean answer left to give.

What the Genome Revealed

For all those millennia the plant kept its own instructions to itself, and it was not until 2020 that anyone managed to read them. In that year a large research team led by Xu Sun published, in the journal Molecular Plant, the first chromosome-level genome sequence of garlic — the first for any member of the genus Allium at all, a group whose famously vast genomes had long defeated the sequencing machines. Garlic's proved vast indeed. It runs to something like sixteen billion base pairs — roughly five times the length of the human genome — carried on the plant's eight pairs of chromosomes and encoding an estimated fifty-seven thousand and more protein-coding genes — well over twice the number credited to our own species, and carried on roughly five times as much DNA. The reason for that bulk was written in the sequence itself: the great majority of garlic's DNA is not genes at all but repetitive elements, the self-copying "jumping" sequences called transposons, which had multiplied in a comparatively recent burst and inflated the whole genome like a slowly filling balloon. It was those same repeats that had kept the alliums unread for so long, for assembling billions of near-identical, self-copied stretches into their correct order defeated the older sequencers; it took the newest long-read machines, able to run clean through a whole repeat in a single pass, to set garlic's giant genome in order at last. For this book the most welcome disclosures were the practical ones. The genome laid out the very machinery of the chapter to come — the family of genes that manufacture garlic's stockpiled alliin, and the genes behind the long fructan chains in which the bulb banks its winter sugar — the chemistry of flavour and the chemistry of storage both spelled out at last in the plant's own hand. A plant that will barely breed, whose deepest ancestry is unsettled, and whose flavour is made only by injury, had finally been persuaded to hand over the written instructions for all three.

The Names of the Thing

The names the plant carries are themselves a small record of how it was seen. The English word garlic is one of the oldest food-words in the language, come down from the Old English gār-lēac — literally "spear-leek," the gār a spear and the lēac a leek or pot-herb — a compound that catches at once the plant's kinship, as one of the leek tribe, and its look, the narrow blades and the pointed clove reading to Anglo-Saxon eyes as so many little spears. The Latin the botanists kept, Allium sativum, is plainer and just as telling: allium, the old Roman name for garlic and its relations, and sativum, "sown" or "cultivated," the epithet Linnaeus reserved for a domesticated crop as against its wild kin. A spear-leek that is grown rather than gathered — the two names between them hold the plant's shape, its family, and the single most important fact of its long career: that it is, and has for millennia been, a creature of the garden and not the wood.

A Family of Sharp Relations

Garlic does not stand alone. It is one species, Allium sativum, in a large and characterful genus — Harold McGee, in the line that opens this chapter, put it at "around 500 species," a fair count for his edition, though the botanists' tally has since climbed toward nine hundred or a thousand as old species are split and new ones described, many of them from that same Central Asian heartland. However the species are counted, the family resemblance is written in every kitchen that has ever made a person cry. McGee places the alliums in the "lily family," which was the standard botany of his day; the taxonomists have since moved them out of that old catch-all. Modern molecular phylogenetics broke the sprawling lilies apart, and the onions went first into a family of their own, the Alliaceae, and then, in the classifications that carry the sober names APG III (2009) and APG IV (2016), were folded into the Amaryllis family, the Amaryllidaceae, as its own onion-scented subfamily, the Allioideae — so that garlic now sits, on the herbarium sheet, as a cousin of the daffodil. The reclassification changes nothing on the plate and a good deal in the filing cabinet. What unites the whole genus is not shape, which ranges from garlic's clustered head to the onion's single globe to the chive's slender tuft, but chemistry: every true allium carries the same latent armoury of sulphur compounds, the subject of the next chapter, released as pungency the moment the plant is cut.

The near relations are worth naming, because to know the family is to place garlic within it. The onion, Allium cepa, is the great single-bulbed cousin, storing its reserves in one swollen globe of concentric leaves rather than a cluster of cloves. The leek and the coarse elephant garlic are forms of Allium ampeloprasum, and here a small honesty is owed: elephant garlic, for all its enormous mild cloves, is not true garlic at all but a kind of leek that happens to bulb like one, which is why its flavour is so gentle. The shallot is a clustering, clove-forming onion, closer in habit to garlic than to its own parent species. The chive, Allium schoenoprasum, is the delicate grassy member grown for its leaves; the garlic chive, A. tuberosum, a flat-leaved Asian relation that tastes, aptly, of both. And in the woods of two continents grow the wild ones the foragers prize — the European ramson or bear's garlic, A. ursinum, carpeting spring woodland with its broad pungent leaves, and the North American ramp, A. tricoccum, its rarer, fiercely sought counterpart. The forager who gathers the European ramson should carry one caution, and it is the family's own chemistry that supplies the safeguard: ramsons share their shady spring woods with two of the deadliest plants in the northern flora — the lily-of-the-valley, whose leaves hold heart-stopping cardiac glycosides, and the autumn crocus, whose colchicine can kill from as few as three or four leaves — and every season both are eaten in mistake for wild garlic, sometimes fatally. The one reliable test is the plant's defence turned to the gatherer's advantage: crush a leaf, and if it does not breathe out the unmistakable smell of garlic, it is not garlic, for the deadly mimics carry no such scent because they carry no such chemistry. The genus reaches beyond the kitchen, too, into the flower border, where the great drumstick ornamentals such as Allium giganteum raise their violet globes on a metre of stem — bred for the eye, but keeping, in a bruised leaf, the same telltale sulphurous breath. All of them are garlic's kin; all of them hold the same buried secret; and all of them make the same wordless argument that this genus, more than almost any other, is the one humanity cannot cook without.

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<g font-family="'Liberation Sans','DejaVu Sans',sans-serif" font-size="10.5" letter-spacing="2" fill="#43331f" text-anchor="middle"> <text x="100" y="384">GARLIC</text> <text x="200" y="384">ONION</text> <text x="310" y="384">LEEK</text> <text x="416" y="384">SHALLOT</text> <text x="508" y="384">CHIVE</text> <text x="572" y="384">RAMP</text> </g> <text x="320" y="404" text-anchor="middle" font-family="'Liberation Sans','DejaVu Sans',sans-serif" font-size="8" letter-spacing="2.5" fill="#6f5a40" font-style="italic">THE ALLIUM FAMILY</text> </svg>

<figcaption><em>Plate 3. The allium family: garlic, onion, leek, shallot, chive and wild ramson set side by side — one genus, many shapes, a single sulphurous secret held in common.</em></figcaption> </figure>

The bulb, then, is a folded plant: a cluster of leaves-turned-larders around a buried stem, cloned across the centuries because it forgot how to seed, grown by the tens of millions of tonnes from cloves that are each a piece of the last, and armed — though the intact clove gives no sign of it — with the family's chemical inheritance. That last point is the one the kitchen cares about most, and it is the deepest mystery of the lot. For a whole clove, sound and unbroken, is very nearly odourless; the ferocious flavour we have come all this way to praise does not yet exist. It waits to be made, in an instant, by an act of violence. To that small, decisive wound the next chapter turns.

[^1]: The restoration of true-seed fertility in cultivated garlic, achieved with wild and semi-wild Central Asian material, is a genuine but partial and relatively recent result; garlic in ordinary cultivation remains propagated entirely from cloves and bulbils. The claim here is that fertility has been recovered in some experimental lines, not that seed-grown garlic has entered general use.

บทถัดไป · 5 / 15Chapter 2 — The Chemistry of Pungency