Black Nightshade

Solanum nigrum, S. americanum, S. ptychanthum, S. douglasii, and other closely allied species
Solanaceae – Nightshade Family

The very word “nightshade” causes many foragers to shudder with apprehension. It seems that everybody has heard of “deadly nightshade” and written off the entire group as too scary to contend with. How lucky we are that our ancestors were more confident in their botanical skills—for the amazing nightshade family has given us many cultivated fruits and vegetables, including potatoes, tomatoes, eggplants, bell peppers, hot peppers, ground cherries, and tomatillos.

Black nightshade is a common weed found on all the inhabited continents. It has a long and well-established history as a food source for numerous cultures around the globe. In fact, it is among the most widely used and well-documented wild foods in the world, rivaled in this respect only by a few other ubiquitous weeds such as lamb’s quarters, amaranth, and stinging nettle. There are probably over two billion people for whom the black nightshade is a regular or occasional item of diet. Yet in the predominantly “white” parts of the world—Europe and North America—the Solanum nigrum complex is widely believed to be extremely poisonous. The contradiction is stark, confusing, and quite amazing.

“The leaves and tender shoots are boiled in the same way as spinach and are eaten in many parts of India . . . The berries, when ripe, are often eaten by children and are sometimes used for preparing pies and preserves.”

—Chopra, Badhwar, and Ghosh, 1965, p. 670.

“Every intelligent child shuns the fruit of this weed . . . the poisonous properties of which are undoubted. Children who have eaten the fruit have died soon after from its effects.”

—“W.W.,”in The Gardener’s Chronicle of London, March 21, 1909.

“Ripe berries . . . are frequently eaten raw as fruits, particularly in parts of Africa. They are also widely used in pies and preserves, and sometimes as a substitute for raisins in plum puddings, particularly in North America. They can also make a delightful jam.”

—Edmonds and Chweya, 1997, pp. 56–57.

“The berries are poisonous, and will produce torpor, insensibility, and death.”

—Brown, 1867, p. 110

“I have eaten pounds of pies, preserves, and fruit sauces made of the ripe berries.”

—Gibbons and Tucker, 1979, p. 251

One can’t help but wonder how such discrepancies can coexist. But before we look at this question in detail, let’s introduce the plant.

Description

Authorities today recognize a number of similar species that used to be lumped together under one name, Solanum nigrum. All of these are called “black nightshade” and exhibit only minor differences. In North America, S. ptychanthum dominates in the East, and S. americanum dominates in the South. The Great Plains is home to S. interius, and S. douglasii is found in the Southwest. S. nigrum is native to the Old World, particularly Europe and the Mediterranean; it is rather rare in North America, where it has been introduced. In most older works, all of these species are called S. nigrum. Today, many authors speak of “the Solanum nigrum complex,” which refers to all of the dozens of black nightshade species around the world formerly called S. nigrum. It is usually impossible to tell from older sources if the plant under discussion would now be classified as S. nigrum or some other species. This account pertains to those members of the S. nigrum complex found in North America. I use the name S. nigrum when referring generally to the black nightshades of this complex. I also use the names originally given in the sources I cite, but readers should be aware of the unique ambiguity of this group.

The black nightshade that abounds in my area, S. ptychanthum, is an annual herb with relatively weak, unarmed, smooth, usually hairless stems that branch widely and freely. Large specimens stand 3 feet (90 cm) high and span 4 feet (120 cm) or more in width, usually with the lower branches resting directly on the ground. However, like most weedy annuals, this plant can be sexually mature at almost any size, sometimes fruiting when no more than 3 inches (8 cm) tall.

The leaves are alternate, dark green, soft, rather thin, and often riddled with bug holes like those of amaranth, which they somewhat resemble. The young leaves may have a coppery or purplish sheen on the underside. The size of the leaves is quite variable, while the shape is moderately so, ranging from ovate to lanceolate to diamond-shaped. The margins may be entire or have sparse, rounded teeth. The leaf surfaces are glabrous or sparsely hairy. Petioles are 1.2–2.5 inches (3–6 cm) long, usually with a faint wing on each side. These wings extend to the branches and main stalk, which often has several short wings or ridges running lengthwise.

The flowers appear as early as June and continue being produced into autumn; they are most prevalent in late summer. Hanging in small clusters from the leaf axils, the blossoms grow on pedicels that are often unequal in length. The inconspicuous five-petaled flowers are whitish and about a half inch across. In form they resemble tomato flowers.

The fruit is almost perfectly spherical, about the size of a pea or a blueberry, green at first but turning purplish black when ripe. They are subtended by a persistent five-parted calyx that is slightly smaller in diameter than the fruit. The skins are somewhat tough, like tomato skins, and encapsulate a soft, juicy interior with numerous seeds.

Our other species of black nightshade are quite similar, although some may be hairier or taller, with fruit that is more or less glossy, or exhibit other minor differences. Readers who wish to separate the individual species will need to refer to more technical botanical manuals, as that is beyond the scope of this book.

There are a number of toxic nightshades that must be avoided. Among these is belladona Atropa belladona, which has been frequently confused with black nightshade (and also shares that common name). Differentiating this plant from black nightshade will be discussed at length later. Bittersweet nightshade Solanum dulcamara, while a member of the same genus as black nightshade, is very easy to tell apart. This species is a semi-woody vine with large, deeply lobed leaves. The striking purple flowers are borne in panicles of about a dozen, ripening later into oblong red berries. Bittersweet nightshade is a common weedy vine of semi-shaded localities and often grows on hedges, fences, and porches. The bright red fruits seem to attract children, but they are somewhat poisonous. Read the above description of black nightshade carefully, as there are a number of other nightshades with toxic fruit.

Range and Habitat

Black nightshade is found just about anywhere in the world where there are weeds. It occupies gardens, yards, agricultural fields, construction sites, and other areas where humans disturb the soil. Natural habitats include river floodplains, steep banks, flooded areas, and storm-damaged woods. It typically persists at a site for only one to three years before being crowded out by perennials, unless the ground is disturbed repeatedly. The seeds can persist viably in the soil for years, waiting for the proper germinating conditions to present themselves. Unlike most weedy species, black nightshade seems to prefer light to moderate shade.

The Mystery of a Myth

Are ripe black nightshade berries toxic?

Let’s take a scientific approach to this question. Two hypotheses have been presented: (1) The ripe berries of black nightshade are edible. (2) The ripe berries of black nightshade are deadly poisonous. (Note that, throughout this discussion, I am referring to the ripe fruit unless otherwise specified.)

Hypothesis 1 is supported by the actions of hundreds of millions of people who have consumed the plant, plus the actions of untold ancestors who have handed the tradition down to them. The literature contains a wealth of information pertaining to the consumption of black nightshade berries. Schilling et al. (1992) report that the berries are eagerly sought and eaten by children in India. They are also eaten in China (Hu, 2005), the Philippines (Siemonsma et al. 1993), Nepal (Manandhar, 2002), Java (Duke, 1987), southern Europe (Couplan, 1998), South Africa (Quin, 1959), New Zealand (Crowe, 2004), and Ethiopia (Guinand and Lemessa, 2001). They were eaten by the Mendocino Indians of California (Chestnut, 1902) as well as the Tubatulabal (Voegelin, 1938). In Turkey, the berries are traditionally used in sweets (Dogan, et al., 2004). Edmonds and Chweya (1997) report the fruit being eaten in Bolivia, Peru, Hawaii, Sierra Leone, Ethiopia, Tanzania, Namibia, South Africa, and Uganda. Some relatively recent wild food authors report their own consumption of these berries (Gibbons and Tucker, 1979; Nyerges, 1999).

Furthermore, black nightshade has been cultivated for over a hundred years in European and American gardens for its edible fruit, sold under the name of “garden huckleberry,” “sunberry,” or “wonderberry.” The wonderberry, now known to be an African species of black nightshade S. retroflexum (Defelice, 2003; Heiser, 1969), and not the special new hybrid that plant breeder Luther Burbank once claimed, was described in a 1909 seed catalog as “like an enormous rich blueberry. Unsurpassed for eating . . . The greatest garden fruit ever introduced” (from Heiser, 1969, p. 64). Relatively recent authors in the United States and England have recommended this fruit for pies and jam (Fisher, 1977; Simms, 1997). A quick Internet search shows that these black nightshades are still available from some seed companies.

I can add my own experience to this list. I began eating wild black nightshade berries at the age of twelve and have avidly sought them since. I have eaten the berries on many hundreds of occasions—sometimes more than a cup at a time. I eat them because I find them delicious. After introducing my wife to them, she decided that we would encourage the volunteers in our garden. In my wild food workshops and in everyday life, I have fed the plant to a few hundred people, most of whom liked the fruit, and none of whom were harmed by it. I have met a few dozen people who, like me, make the berries regular fare when available. Most of them learned this from books or fellow foraging hobbyists, but a few reported that eating black nightshade berries was a family tradition. The same friend who taught me to eat this fruit started feeding them to his son at two years of age.

The conclusion that black nightshade berries are not toxic is supported by additional evidence. In one German study, no alkaloids could be detected in twenty-two samples of ripe fruit of S. nigrum (solanine, atropine, and other nightshade toxins are alkaloids) (Frohne and Pfander, 2005). Cippolini and Levy (1997) state that S. americanum fruit has “negligible levels” of alkaloids. Voss et al. (1993) studied the toxicity of black nightshade berries (S. ptychanthum) in feeding experiments with rats. Even when fed a mixture of ripe and unripe berries as 25 percent of the diet for several weeks, no mortality was observed.

Since untold millions of people eat black nightshade berries, we should see cases of poisoning in the medical literature quite frequently if hypothesis 2 (that the ripe berries are extremely poisonous) is correct. It seems that there would be legal action against the seed companies that sell the plant, or the authors and publishers of the many books that extol its edibility. Contrarily, I can find no record of such a lawsuit, nor of any documented case of poisoning by ripe black nightshade berries in the last fifty years. The evidence is conclusive that black nightshade berries are edible.

However, we are still left with explaining the origin of such a pervasive myth. Literature from the 1800s contains a few accounts of poisoning by ripe S. nigrum berries. These cases seem to be confined to Europe. Chopra et al. (1965) presume that, because the ripe berries are known to be edible, all such accounts refer to unripe berries. This conclusion at first appears sound, but closer examination renders it untenable, since some of the cases specify that ripe berries were the agent of poisoning. Many modern authors cite the fact that the unripe fruits are toxic as justification for the berries’ reputation as deadly, and suggest that this means that the fruit should be avoided entirely. This is nonsense. Unripe mayapples are very toxic (Turner and Szczawinski, 1991) yet this plant’s ripe fruit is not shrouded in horror. In fact, many common fruits are poisonous when unripe, and this doesn’t seem to worry us at all. While the unripe fruits should probably be avoided (although this, too, is disputed by some), and credible poisonings have been attributed to them (Chopra et al. 1965), this in no way justifies or explains the fear with which the plant is typically treated.

A significant observation is that, in the late 1800’s, cases of reported poisoning from ripe black nightshade berries almost completely cease; to the best of my knowledge, the last documented case in the English language occurred in Ireland in 1952 (Towers, 1953). What happened? Certainly, the plant didn’t transform from deadly to delicious over a few generations. And Europeans continue to be affected by other poisonous plants.

The discrepancy in the literature is commonly explained away by the proposition that individual plants vary widely in the toxicity of their berries. This makes no sense; it cannot account for the cessation of reported poisonings, nor can it explain why the poisonings are reported in a limited geographical area. If chemical variability of individual plants accounted for the differing reports of edibility, then we would see poisonings occurring most often where the berries are eaten most often. Instead, the converse is true; the reported poisonings are concentrated in Europe, one of the few places on Earth where the berries are not regularly consumed.

It has also been argued that the toxicity varies on a larger scale, with some populations, species, or subspecies being deadly, while others are edible. Although highly unlikely (there is no known case of plants this closely related having fruit that varies by such extremes), this explanation is conceivable. But again, if this is true, why would the poisonings in Europe have ceased? Why would analysis of European berries show them nontoxic (Bruneton, 1999)? Why would Gerarde and Dioscorides, both Europeans, call them harmless (Defelice, 2003)? Why would Couplan (1998) claim that the ripe berries are eaten raw or cooked in parts of southern Europe? Where are the documented cases of poisoning?

Even in Europe, the toxicity of S. nigrum berries has always been disputed. The famous botanist Michel-Felix Dunal (1813) of Montpellier, France, ate the berries on several occasions and claimed them harmless. This made quite an impression on his contemporaries, and he was much quoted by incredulous Nineteenth-century authors. Balfour (1873, p. 462) stated of S. nigrum, “It contains a small amount of solanine in the juice of the stem and berries, but it may be eaten as food, as in France.” François Couplan, Europe’s leading authority on edible wild plants, tells me that he eats these berries often and loves their addictive taste. He adds that, while people in Europe generally believe them poisonous, there is “no toxicity whatsoever” in the ripe fruit (pers. comm., 2009).

Fortunately, there is a perfectly good explanation for all of this. In Europe there is another plant sometimes known as black nightshade: Atropa belladonna, a well-known poisonous plant that has been used for centuries in medicine and murder. The primary toxic (and medicinal) constituent of Atropa belladonna is atropine, which causes a whole suite of neurological and physiological effects. Common names for this plant include “belladonna” and “deadly nightshade”; unfortunately, due to its black berries, it is also occasionally called “black nightshade.” The shared common name makes confusion likely, and the physical similarities of the plants only exacerbate the problem. Elizabeth Daly’s 1963 novel Deadly Nightshade, the plot of which revolves around a case of poisoning by nightshade berries, demonstrates how false conclusions are an easy task for the lazy or uninformed. At one point, Daly’s detective says, “Solanum nigrum Linnaeus. Also ‘Black, Deadly, or Garden Nightshade. Also Atropa belladonna.’ That’s the poison.”

Daly’s mistake has been made again and again; it inundates the older literature, and is still made with frightful regularity today. I am convinced that this confusion accounts for the reputation of ripe S. nigrum berries as toxic. I am not the first to conclude this; Dunal (1813) made exactly the same argument 200 years ago in France. Displaying the fear-mongering suspension of logic that often accompanies the discussion of black nightshade berries (and wild foods in general), one of Dunal’s critics made a strident but worthless effort to discredit him by pointing out that the raw leaves have caused poisonings, stating that this “places beyond doubt the often contested toxic properties” of S. nigrum (Tardieu and Roussin, 1875, p. 925, translation mine). Of course, this has nothing to do with the berries. Interestingly, in French, S. nigrum and Atropa belladonna also share common names, and the idea that S. nigrum berries are extremely toxic is still deeply entrenched in France today. As in the English sources, older accounts of black nightshade poisonings in France are highly suspect, such as a case reported by Dufeillay (1838), in which the poisoned children described the berries as red.

The confusion between Atropa belladonna and Solanum nigrum is a problem that has long been recognized in the English-speaking countries as well. In a medical treatise on treating cases of poisoning, Murrell (1884, p. 111) says that S. nigrum is often mistaken for belladonna, adding, “Medical witnesses and coroners often wrong on this point.” In A Manual of Toxicology, John James Reese (1874, p. 450) states that

“There is great discrepancy among authorities about the poisonous properties of the above two species of Solanum [dulcamara and nigrum]. . . . Some have supposed that the cases of poisoning that have been ascribed to the two species were, in reality, to be accredited to the Deadly Nightshade (belladonna), which had been mistaken for the others.”

The following anecdote shows that the confusion has gone both ways:

“Solanum Nigrum has often been mistaken for Belladonna. A physician in Ohio confidently said to me, that Belladonna grew plentifully in every part of his county, and upon my questioning the accuracy of his statement, he produced a very fine specimen of Solanum Nigrum, saying, ‘If that is not Belladonna, what is it?’”

—Hoyt, 1874, p. 374

Indeed, the poisoning symptoms described in the old accounts usually suggest atropine poisoning rather than that of solanine. The fact that this myth originated in Europe, the primary natural range of belladonna, and has persisted most tenaciously there, lends further support to this conclusion. In contradistinction to the case with S. nigrum, the medical literature contains hundreds of cases of poisoning by Atropa belladonna berries. These cases are easily found and consistent in their described symptoms, and many of them occur quite recently. When you consider that S. nigrum is a far more common and widespread plant, eaten regularly around the world, there should be millions of such cases if it were equally poisonous. This is perhaps an appropriate place to point out another obvious fact: myths of toxicity are commonplace (in fact, I’d argue that they are a universal feature of human culture) while myths of edibility are exceedingly rare, since they are soon discredited.

People have an amazing ability to make our observations coincide with a preconceived belief (see Don’t Make it Fit, p. 33). In 1978, a red panda escaped from a zoo in Holland. Local newspapers informed the public, in hopes that the animal could be recaptured, but by this time, the panda had already been found dead near the zoo. Yet over a hundred sightings of the panda were reported, all of which occurred after the animal was dead (Feder, 1996). These people weren’t reporting the panda because they had seen it; they were seeing the panda because it had been reported. Similarly, it seems that reports of poisoning from black nightshade berries occurred because the plant was believed to be toxic, rather than the converse.

The black nightshade is not the only European plant to be subject to a toxicity myth of such stark contrast to reality. As surprising as it sounds, the parsnip Pastinaca sativa, the very same plant that is available in markets and grocery stores all across the northern hemisphere, which has been grown for thousands of years for its esculent roots, is widely reported in wildflower books to be deadly poisonous. This myth, like the black nightshade myth, probably arose as a way of keeping people from collecting the plant in the wild and confusing it with toxic relatives.

By the late 1800s, at least in the United States, some authorities began to cautiously challenge the myth. Behr (1889, p. 201) says, “It is not poisonous in California, at least under ordinary circumstances. The same species is common in Europe, where it is considered poisonous.” In 1905, Botany professor Charles Bessey wrote a letter to American Botanist regarding this inversion of thought:

“[This] reminds me of an incident which occurred in my class in Botany nearly thirty five years ago. I was lecturing on the properties of the plants constituting the Solanaceae, and, as a matter of course, said that the berries of the black nightshade (Solanum nigrum) were poisonous. A young fellow from Fort Dodge, Iowa, spoke up and said that the people in his neighborhood made them into pies, preserves, etc. and ate freely of them. I answered him, as became a professor of botany, by saying that as it was well known that black nightshade berries are poisonous, the student must have been mistaken. . . . After a while, however, I learned that the people in central and western Iowa actually did eat black nightshade berries, and they were not poisoned either. Later, I learned the same thing in Nebraska for this species.”

Since then, the obvious fact that black nightshade berries are not deadly poisonous has been slowly and reluctantly accepted. This is often expressed with guarded language and reservation, but at other times it is stated plainly that the berries are edible and delicious. Most scholarly works since about 1960 agree that the ripe berries of the S. nigrum group are edible or at least nontoxic.

Interestingly, despite the fact that enormous numbers of ethnographic sources describe the berries being used as food, and despite the fact that legions of people willingly, gladly, and repeatedly eat them, the wild food literature has become one of the loudest voices contributing to the fear that surrounds this plant. Peterson’s field guide (1977) lists it as “poisonous,” accompanied by a skull and crossbones. Elias and Dykeman (1982) lump it with other nightshades as poisonous. Henderson (2000, p. 189) nebulously suggests an unspecified danger: “Although some nightshades actually bear edible fruit, none of them are worth the risk.” Tull (1987, p. 186) says, “ I consider the whole plant potentially deadly and leave it alone.” (Here she misleadingly cites Heiser [1969], but in that source Heiser’s discussion of black nightshade’s toxicity is poorly constructed, conjectural, and flippant—and he tells us that he made and ate a black nightshade pie!) Many other wild food books take the very reasonable position of not discussing the matter. However, I am proud to align myself with the significant minority of authors (Gibbons and Tucker, 1979; Nyerges, 1999; Couplan, 1998; Van Wyk, 2005) who unabashedly proclaim the ripe fruit edible.

Still, I wondered if, very rarely, ripe black nightshade berries contain an abnormally and dangerously high concentration of solanine. It seems possible. Put into perspective, this fact shouldn’t even be particularly alarming; virtually all edible plants contain toxic compounds. There are numerous documented poisonings from potatoes Solanum tuberosum, several of which have resulted in death (McMillan and Thompson, 1979; Bruneton, 1999; Hansen, 1925). Curly dock Rumex crispus remains a popular wild edible, despite the fact that, rather recently, a man apparently overindulged on the leaves and killed himself (Xirgu et al., 1989). Does this happen with black nightshade? With this question in mind, I sought the last reported case of poisoning (nonlethal, incidentally) by ripe black nightshade berries, which occurred in Ireland and was recorded in an article entitled, “A Case of Poisoning by Solanum nigrum” (Towers, 1953).

Here, again, is a case of name misapplication. Throughout the article, there is conclusive evidence that the plant that was actually responsible for this poisoning was Atropa belladonna. The victim’s description of the plant and its berries strongly suggests belladonna, and is scarcely compatible with the characteristics of S. nigrum. The symptoms described clearly fit those associated with atropine (the primary toxin in belladonna) rather than solanine (the toxin found in unripe black nightshade berries). I was prepared to carefully advance this argument, but fortunately our good Dr. Towers does this himself—unwittingly testifying convincingly against his own conclusions. He attests (p. 79), “Having thus reviewed the pharmacology of atropine, it is possible to see that this case under discussion shows most of the classical features associated with the drug.” However, atropine is not found in S. nigrum; it is commercially extracted from Atropa belladonna, from which its name is derived. Towers apparently was unaware of this. He clearly writes under the assumption that what is true of one of these nightshade is also applicable to the other. The prevalence of this irresponsible attitude makes careless investigation of this plant no surprise. Indeed, the two-page commentary following the clinical notes mentions S. nigrum only once, in the first sentence. Amazingly, thereafter, the text refers only to belladonna and atropine. Towers concludes (p. 80) by stating that the victim’s symptoms “fit in with the classical features of poisoning by atropine caused by eating berries of the deadly nightshade type.” The name “deadly nightshade” is properly applied to belladonna, not S. nigrum (although it is often mistakenly applied), and of the two species, only belladonna contains atropine. By this point, his article has quietly transformed into “a case of poisoning by Atropa belladonna”—which should have been its title.

Through an extensive search of literary sources and correspondence with experts (including Jennifer Edmonds, probably the world’s leading authority on black nightshades), I have been unable to locate a single credible, documented case of poisoning from the ripe berries of any member of the S. nigrum complex. There is simply no basis for the contention that they are toxic.

The Second Myth: Black Nightshade Greens

As well documented as black nightshade berries are as a food source, the greens are even better documented. In fact, they are perhaps the most commonly eaten wild greens in the world. Black nightshade greens are regularly consumed in virtually every tropical and subtropical country on Earth, as well as occasionally in the temperate zones. Again, European and North American literature often calls these greens poisonous or deadly, but authors from the tropics hold a completely different attitude. Consider this:

“The tender shoots, young leaves and unripe green fruits are eaten as a vegetable, raw, cooked or steamed (for 5–10 minutes), alone or in combination with other vegetables. . . . S. americanum is used as a green vegetable throughout South-East Asia and the green fruits can be bought in the local markets. It is common in the vegetable assortment of large supermarkets. . . . Being a common crop of home gardens and a common weed of cultivation, its importance is considerable.”

—Siemonsma and Pilvek, 1993, p. 253

These authors conclude their account by suggesting that black nightshade should receive more research attention as a food crop. Nowhere in their rather lengthy treatment of this plant do they even mention any concern over toxicity. And note their repeated mentioning of the green fruits as food. (Be aware, however, that analyses have clearly shown the green fruit of at least some species to contain high levels of solanine. I advise against eating them.)

Chopra et al. (1965, p. 670) tell us, “The leaves and tender shoots are boiled in the same way as spinach and are eaten in many parts of India.” The young greens are eaten in Vietnam (Tanaka and Ke, 2007), Nepal (Manandhar, 2002), and China (Hu, 2005). Couplan (1998) says that black nightshade greens are the most popular vegetable in Madagascar; he says (pers. comm., 2009) that they are eaten at “almost every meal.” In three villages in Tanzania, Fleuret (1979) found black nightshade to be the second most commonly eaten wild green—only amaranth was eaten more. The greens were also sold in local markets. Purseglove (1968, p. 65) says that S. nigrum “is extensively used as a pot-herb in Africa and Asia, in spite of the fact that it is reputed to be poisonous in Europe.” Heiser (1969) found the greens regularly for sale in vegetable markets in Guatemala. Edmonds and Chweya (1997, p. 56) summarize, “Leaves and tender shoots are widely used as vegetables throughout the world . . . All the species [of black nightshade] are used as pot-herbs or leaf/stem vegetables more or less throughout their respective ranges in Africa, Asia, Malesia and the Americas.” They record the greens being consumed in Guatemala, Mauritius, Hawaii, Papua New Guinea, the Seychelles, Australia, Greece, and fourteen African countries. Black nightshade greens are eaten so frequently and widely that documenting it in this way is as superfluous as documenting the edibility of onions.

Looking to uphold the Western notion that this plant is deadly poisonous, some suggest that the edibility of tropical forms differs from ours. There is nothing to support this idea. The most widespread black nightshade of the Old and New World tropics is S. americanum (Edmonds and Chweya, 1997), but this species is also widespread in the United States. Black nightshade was said to be “the most relished potherb” of the Cherokee (Witthoft, 1947). Couplan (1998) reports it being eaten in southern Europe. In Wisconsin, Minnesota, and surely elsewhere in the United States, black nightshade greens are actively sought and regularly eaten by Hmong immigrants.

But some Americans desperately want us to disbelieve this plant’s edibility. Based on her interpretation of one anecdotal account, Fackelmann (1993) conjectures that people who eat black nightshade greens must first undergo a lengthy process of building up a tolerance to solanine—otherwise they will be poisoned. Although she provides no scientific evidence to support this specious and ridiculous claim, it has been widely accepted as fact. Fackelmann makes it sound as if only a few obscure, impoverished cultures eat this vegetable, when in fact it is a common food for hundreds of millions of people in dozens of countries, sold in grocery stores and produce markets. The tone of her article is condescending and ethnocentric. I know several Americans, including myself, who have eaten these greens safely without building up a tolerance. This doesn’t mean that black nightshade greens can be used without caution; they sometimes contain the toxin solanine (Frohne and Pfander, 2005). For guidelines on their safe use, see the preparation section on pages 390–392.

Harvest and Preparation

Berries: Black nightshade berries are delicious, abundant, widespread, and easy to harvest. Only eat the ripe berries, which turn juicy and dark purple-black. (A few species, such as S. villosum, have berries that ripen to yellow or orange, but these are not commonly found in North America.) Do not eat partially ripe berries that still contain green lines, and do not eat ripe berries if they taste bitter or unpleasant to you. As always, eat small portions your first
few times.

Don’t imagine that black nightshade berries are a substitute for blueberries or any other familiar fruit. Their flavor is most like that of ground-cherries (genus Physalis)—like fruity tomatoes. Generally, I eat the berries raw. Whenever I happen upon a plant bearing ripe fruit, I eat as many as time or the supply allows. They are excellent in salad—although being perfectly round they tend to roll off your fork, and they’re usually too small to spear with a tine. Alas, the conundrums of a forager. I also like them in tacos or burritos, where they aren’t so mobile. They are good in certain soups or pasta dishes.

Black nightshade berries are also used to make uniquely delicious fruit sauces and jams. They remind me of ground-cherries, blueberries, and tomatoes, but their tiny seeds are slightly hot, especially when cooked. (To get in the right mood for this chapter, I savored some nightshade jam from our refrigerator.) The flavor and texture can be altered by straining out the skins and seeds. They make good pies, and a few can be added to applesauce to enhance the color.

Black nightshade berries begin ripening in midsummer and continue late into the fall, often past light frosts. It is not uncommon to find flowers, unripe fruit, and ripe fruit on the plant at the same time. I have no special tricks for picking them, which I typically do while sitting comfortably beside a prolific plant. The branches droop and the fruit is often borne near the ground; in this case, wash the berries carefully. From the best plants you might get over a quart of fruit, but it will go as slowly as picking blueberries.

I was once exploring an acquaintance’s garden with him. When I found a black nightshade plant loaded with fruit and began eating them, he said, “Nightshade? My grandmother used to make nightshade sauce when I was little, but I never knew what nightshade she used.” He tasted a handful, smiled at the flavor, then confirmed, “Oh yeah, this was definitely it.” We talked a little of the sweet nightshade sauce that his grandmother in South Dakota made, which the family relished on pancakes and ice cream. He remembered this sauce fondly, saying that as a child he “wanted all he could get.”

Greens: The young, tender leafy shoots of black nightshade, before the plants have flowered, make an excellent potherb—in my opinion equal in quality to amaranth and lamb’s quarters. Gather thick, juicy shoots that stand upright, snap easily when bent, and do not need to be cut. You will find these mostly in early or mid summer. They should be boiled before being eaten. Their rich, mild flavor and soft texture leave no question as to why they are a popular vegetable in much of the world. The older growth, however, is bitter and should be avoided.

Although the greens are the most commonly eaten part of black nightshade worldwide, they contain varying amounts of the bitter toxin solanine. (Solanine is also found in tomatoes, potatoes, eggplants, bell peppers, and even cherries.) As with the ripe berries, I have been unable to find any documented cases of poisoning from eating the properly cooked young greens. Although Edmonds and Chweya (1997) report that toxic alkaloids are not present in the vegetative parts of the plant, others have reported solanine in some leaf samples (Frohne and Pfander, 2005).

The youngest, tenderest shoots are generally not bitter. As the plants age, the bitterness (and presumably, the solanine content) increases—sometimes substantially. I reiterate here that the older growth, or any greens that are distastefully bitter, should not be eaten. Marshall (2001) interviewed villagers in Kenya and found that, while black nightshade was the most favored and most commonly eaten green, they recognized and avoided those with certain subtle characteristics that denoted bitterness (older, tougher, drier stems with full-grown leaves, especially stems that spread horizontally). Marshall reported that her informants preferred it because, unlike amaranth, it could be eaten every day without making one feel sick.

The bitter quality of black nightshade greens has been overemphasized by Western authors whose attitude about the plant is irrationally negative. After all, many of our more popular greens are bitter (dandelion, chicory, escarole), toxic when raw (marsh marigold), or toxic when too old (pokeweed).  When collected  at the correct stage and prepared properly, black nightshade greens are not only safe to eat, but are a palatable, nutritious, and wholesome food.

When collecting black nightshade greens, follow these guidelines to avoid ingesting excessive solanine: (1) harvest only the young, tender growth, generally before the plants flower. (2) Boil them in a full pot of water for ten to fifteen minutes, drain the water, and repeat this process if any bitterness remains. (3) Do not eat oversized portions. (4) Do not eat them if you find the bitterness strong or distasteful. (5) Stick to those species which have a well-established traditional use as food. (Among North American species, this means S. americanum and S. ptychanthum.)

Some Western authors, attempting to explain away the obvious edibility of a plant that their culture erroneously believes to be poisonous, suggest that black nightshade greens are eaten regularly by hundreds of millions of people only because of their medicinal properties. It is true that this plant is traditionally considered a health tonic by many cultures, as well as a remedy for numerous ailments, including malaria, dysentery, and schistosomiasis (Gbile and Adesina, 1988). Studies have also demonstrated that these greens have antiviral, anticancer, and antiparasitic properties (Gbile and Adesina, 1988; Bose and Ghosh, 1980). However, these are secondary benefits; most people who eat these greens clearly do so because they like them and are hungry. Black nightshade greens are also extremely nutritious, providing a much appreciated rich source of proteins, amino acids, minerals, and vitamins (Edmonds and Chweya, 1997).

Some who remain afraid to try black nightshade act as if those of us who eat it are foolish and irresponsible. Meanwhile, hundreds of millions of people eat it anyway. I counter that it is irresponsible, and a bit ethnocentric, to insist on perpetuating this myth in the absence of any supporting evidence. After all, both the tomato and potato were once considered poisonous in Europe.

Solanum nigrum, S. americanum, S. ptychanthum, S. douglasii, and other closely allied species

Solanaceae – Nightshade Family

T

he very word “nightshade” causes many foragers to shudder with apprehension. It seems that everybody has heard of “deadly nightshade” and written off the entire group as too scary to contend with. How lucky we are that our ancestors were more confident in their botanical skills—for the amazing nightshade family has given us many cultivated fruits and vegetables, including potatoes, tomatoes, eggplants, bell peppers, hot peppers, ground cherries, and tomatillos.

Black nightshade is a common weed found on all the inhabited continents. It has a long and well-established history as a food source for numerous cultures around the globe. In fact, it is among the most widely used and well-documented wild foods in the world, rivaled in this respect only by a few other ubiquitous weeds such as lamb’s quarters, amaranth, and stinging nettle. There are probably over two billion people for whom the black nightshade is a regular or occasional item of diet. Yet in the predominantly “white” parts of the world—Europe and North America—the Solanum nigrum complex is widely believed to be extremely poisonous. The contradiction is stark, confusing, and quite amazing.

“The leaves and tender shoots are boiled in the same way as spinach and are eaten in many parts of India . . . The berries, when ripe, are often eaten by children and are sometimes used for preparing pies and preserves.”

—Chopra, Badhwar, and Ghosh, 1965, p. 670.

“Every intelligent child shuns the fruit of this weed . . . the poisonous properties of which are undoubted. Children who have eaten the fruit have died soon after from its effects.”

“W.W.,”in The Gardener’s Chronicle of London, March 21, 1909.

“Ripe berries . . . are frequently eaten raw as fruits, particularly in parts of Africa. They are also widely used in pies and preserves, and sometimes as a substitute for raisins in plum puddings, particularly in North America. They can also make a delightful jam.”

—Edmonds and Chweya, 1997, pp. 5657.

“The berries are poisonous, and will produce torpor, insensibility, and death.”

—Brown, 1867, p. 110

“I have eaten pounds of pies, preserves, and fruit sauces made of the ripe berries.”

—Gibbons and Tucker, 1979, p. 251

One can’t help but wonder how such discrepancies can coexist. But before we look at this question in detail, let’s introduce the plant.

Description

Authorities today recognize a number of similar species that used to be lumped together under one name, Solanum nigrum. All of these are called “black nightshade” and exhibit only minor differences. In North America, S. ptychanthum dominates in the East, and S. americanum dominates in the South. The Great Plains is home to S. interius, and S. douglasii is found in the Southwest. S. nigrum is native to the Old World, particularly Europe and the Mediterranean; it is rather rare in North America, where it has been introduced. In most older works, all of these species are called S. nigrum. Today, many authors speak of “the Solanum nigrum complex,” which refers to all of the dozens of black nightshade species around the world formerly called S. nigrum. It is usually impossible to tell from older sources if the plant under discussion would now be classified as S. nigrum or some other species. This account pertains to those members of the S. nigrum complex found in North America. I use the name S. nigrum when referring generally to the black nightshades of this complex. I also use the names originally given in the sources I cite, but readers should be aware of the unique ambiguity of this group.

The black nightshade that abounds in my area, S. ptychanthum, is an annual herb with relatively weak, unarmed, smooth, usually hairless stems that branch widely and freely. Large specimens stand 3 feet (90 cm) high and span 4 feet (120 cm) or more in width, usually with the lower branches resting directly on the ground. However, like most weedy annuals, this plant can be sexually mature at almost any size, sometimes fruiting when no more than 3 inches (8 cm) tall.

The leaves are alternate, dark green, soft, rather thin, and often riddled with bug holes like those of amaranth, which they somewhat resemble. The young leaves may have a coppery or purplish sheen on the underside. The size of the leaves is quite variable, while the shape is moderately so, ranging from ovate to lanceolate to diamond-shaped. The margins may be entire or have sparse, rounded teeth. The leaf surfaces are glabrous or sparsely hairy. Petioles are 1.22.5 inches (36 cm) long, usually with a faint wing on each side. These wings extend to the branches and main stalk, which often has several short wings or ridges running lengthwise.

The flowers appear as early as June and continue being produced into autumn; they are most prevalent in late summer. Hanging in small clusters from the leaf axils, the blossoms grow on pedicels that are often unequal in length. The inconspicuous five-petaled flowers are whitish and about a half inch across. In form they resemble tomato flowers.

The fruit is almost perfectly spherical, about the size of a pea or a blueberry, green at first but turning purplish black when ripe. They are subtended by a persistent five-parted calyx that is slightly smaller in diameter than the fruit. The skins are somewhat tough, like tomato skins, and encapsulate a soft, juicy interior with numerous seeds.

Our other species of black nightshade are quite similar, although some may be hairier or taller, with fruit that is more or less glossy, or exhibit other minor differences. Readers who wish to separate the individual species will need to refer to more technical botanical manuals, as that is beyond the scope of this book.

There are a number of toxic nightshades that must be avoided. Among these is belladona Atropa belladona, which has been frequently confused with black nightshade (and also shares that common name). Differentiating this plant from black nightshade will be discussed at length later. Bittersweet nightshade Solanum dulcamara, while a member of the same genus as black nightshade, is very easy to tell apart. This species is a semi-woody vine with large, deeply lobed leaves. The striking purple flowers are borne in panicles of about a dozen, ripening later into oblong red berries. Bittersweet nightshade is a common weedy vine of semi-shaded localities and often grows on hedges, fences, and porches. The bright red fruits seem to attract children, but they are somewhat poisonous. Read the above description of black nightshade carefully, as there are a number of other nightshades with toxic fruit.

Range and Habitat

Black nightshade is found just about anywhere in the world where there are weeds. It occupies gardens, yards, agricultural fields, construction sites, and other areas where humans disturb the soil. Natural habitats include river floodplains, steep banks, flooded areas, and storm-damaged woods. It typically persists at a site for only one to three years before being crowded out by perennials, unless the ground is disturbed repeatedly. The seeds can persist viably in the soil for years, waiting for the proper germinating conditions to present themselves. Unlike most weedy species, black nightshade seems to prefer light to moderate shade.

The Mystery of a Myth

Are ripe black nightshade berries toxic?

Let’s take a scientific approach to this question. Two hypotheses have been presented: (1) The ripe berries of black nightshade are edible. (2) The ripe berries of black nightshade are deadly poisonous. (Note that, throughout this discussion, I am referring to the ripe fruit unless otherwise specified.)

Hypothesis 1 is supported by the actions of hundreds of millions of people who have consumed the plant, plus the actions of untold ancestors who have handed the tradition down to them. The literature contains a wealth of information pertaining to the consumption of black nightshade berries. Schilling et al. (1992) report that the berries are eagerly sought and eaten by children in India. They are also eaten in China (Hu, 2005), the Philippines (Siemonsma et al. 1993), Nepal (Manandhar, 2002), Java (Duke, 1987), southern Europe (Couplan, 1998), South Africa (Quin, 1959), New Zealand (Crowe, 2004), and Ethiopia (Guinand and Lemessa, 2001). They were eaten by the Mendocino Indians of California (Chestnut, 1902) as well as the Tubatulabal (Voegelin, 1938). In Turkey, the berries are traditionally used in sweets (Dogan, et al., 2004). Edmonds and Chweya (1997) report the fruit being eaten in Bolivia, Peru, Hawaii, Sierra Leone, Ethiopia, Tanzania, Namibia, South Africa, and Uganda. Some relatively recent wild food authors report their own consumption of these berries (Gibbons and Tucker, 1979; Nyerges, 1999).

Furthermore, black nightshade has been cultivated for over a hundred years in European and American gardens for its edible fruit, sold under the name of “garden huckleberry,” “sunberry,” or “wonderberry.” The wonderberry, now known to be an African species of black nightshade S. retroflexum (Defelice, 2003; Heiser, 1969), and not the special new hybrid that plant breeder Luther Burbank once claimed, was described in a 1909 seed catalog as “like an enormous rich blueberry. Unsurpassed for eating . . . The greatest garden fruit ever introduced” (from Heiser, 1969, p. 64). Relatively recent authors in the United States and England have recommended this fruit for pies and jam (Fisher, 1977; Simms, 1997). A quick Internet search shows that these black nightshades are still available from some seed companies.

I can add my own experience to this list. I began eating wild black nightshade berries at the age of twelve and have avidly sought them since. I have eaten the berries on many hundreds of occasions—sometimes more than a cup at a time. I eat them because I find them delicious. After introducing my wife to them, she decided that we would encourage the volunteers in our garden. In my wild food workshops and in everyday life, I have fed the plant to a few hundred people, most of whom liked the fruit, and none of whom were harmed by it. I have met a few dozen people who, like me, make the berries regular fare when available. Most of them learned this from books or fellow foraging hobbyists, but a few reported that eating black nightshade berries was a family tradition. The same friend who taught me to eat this fruit started feeding them to his son at two years of age.

The conclusion that black nightshade berries are not toxic is supported by additional evidence. In one German study, no alkaloids could be detected in twenty-two samples of ripe fruit of S. nigrum (solanine, atropine, and other nightshade toxins are alkaloids) (Frohne and Pfander, 2005). Cippolini and Levy (1997) state that S. americanum fruit has “negligible levels” of alkaloids. Voss et al. (1993) studied the toxicity of black nightshade berries (S. ptychanthum) in feeding experiments with rats. Even when fed a mixture of ripe and unripe berries as 25 percent of the diet for several weeks, no mortality was observed.

Since untold millions of people eat black nightshade berries, we should see cases of poisoning in the medical literature quite frequently if hypothesis 2 (that the ripe berries are extremely poisonous) is correct. It seems that there would be legal action against the seed companies that sell the plant, or the authors and publishers of the many books that extol its edibility. Contrarily, I can find no record of such a lawsuit, nor of any documented case of poisoning by ripe black nightshade berries in the last fifty years. The evidence is conclusive that black nightshade berries are edible.

However, we are still left with explaining the origin of such a pervasive myth. Literature from the 1800s contains a few accounts of poisoning by ripe S. nigrum berries. These cases seem to be confined to Europe. Chopra et al. (1965) presume that, because the ripe berries are known to be edible, all such accounts refer to unripe berries. This conclusion at first appears sound, but closer examination renders it untenable, since some of the cases specify that ripe berries were the agent of poisoning. Many modern authors cite the fact that the unripe fruits are toxic as justification for the berries’ reputation as deadly, and suggest that this means that the fruit should be avoided entirely. This is nonsense. Unripe mayapples are very toxic (Turner and Szczawinski, 1991) yet this plant’s ripe fruit is not shrouded in horror. In fact, many common fruits are poisonous when unripe, and this doesn’t seem to worry us at all. While the unripe fruits should probably be avoided (although this, too, is disputed by some), and credible poisonings have been attributed to them (Chopra et al. 1965), this in no way justifies or explains the fear with which the plant is typically treated.

A significant observation is that, in the late 1800’s, cases of reported poisoning from ripe black nightshade berries almost completely cease; to the best of my knowledge, the last documented case in the English language occurred in Ireland in 1952 (Towers, 1953). What happened? Certainly, the plant didn’t transform from deadly to delicious over a few generations. And Europeans continue to be affected by other poisonous plants.

The discrepancy in the literature is commonly explained away by the proposition that individual plants vary widely in the toxicity of their berries. This makes no sense; it cannot account for the cessation of reported poisonings, nor can it explain why the poisonings are reported in a limited geographical area. If chemical variability of individual plants accounted for the differing reports of edibility, then we would see poisonings occurring most often where the berries are eaten most often. Instead, the converse is true; the reported poisonings are concentrated in Europe, one of the few places on Earth where the berries are not regularly consumed.

It has also been argued that the toxicity varies on a larger scale, with some populations, species, or subspecies being deadly, while others are edible. Although highly unlikely (there is no known case of plants this closely related having fruit that varies by such extremes), this explanation is conceivable. But again, if this is true, why would the poisonings in Europe have ceased? Why would analysis of European berries show them nontoxic (Bruneton, 1999)? Why would Gerarde and Dioscorides, both Europeans, call them harmless (Defelice, 2003)? Why would Couplan (1998) claim that the ripe berries are eaten raw or cooked in parts of southern Europe? Where are the documented cases of poisoning?

Even in Europe, the toxicity of S. nigrum berries has always been disputed. The famous botanist Michel-Felix Dunal (1813) of Montpellier, France, ate the berries on several occasions and claimed them harmless. This made quite an impression on his contemporaries, and he was much quoted by incredulous Nineteenth-century authors. Balfour (1873, p. 462) stated of S. nigrum, “It contains a small amount of solanine in the juice of the stem and berries, but it may be eaten as food, as in France.” François Couplan, Europe’s leading authority on edible wild plants, tells me that he eats these berries often and loves their addictive taste. He adds that, while people in Europe generally believe them poisonous, there is “no toxicity whatsoever” in the ripe fruit (pers. comm., 2009).

Fortunately, there is a perfectly good explanation for all of this. In Europe there is another plant sometimes known as black nightshade: Atropa belladonna, a well-known poisonous plant that has been used for centuries in medicine and murder. The primary toxic (and medicinal) constituent of Atropa belladonna is atropine, which causes a whole suite of neurological and physiological effects. Common names for this plant include “belladonna” and “deadly nightshade”; unfortunately, due to its black berries, it is also occasionally called “black nightshade.” The shared common name makes confusion likely, and the physical similarities of the plants only exacerbate the problem. Elizabeth Daly’s 1963 novel Deadly Nightshade, the plot of which revolves around a case of poisoning by nightshade berries, demonstrates how false conclusions are an easy task for the lazy or uninformed. At one point, Daly’s detective says, “Solanum nigrum Linnaeus. Also ‘Black, Deadly, or Garden Nightshade. Also Atropa belladonna.’ That’s the poison.”

Daly’s mistake has been made again and again; it inundates the older literature, and is still made with frightful regularity today. I am convinced that this confusion accounts for the reputation of ripe S. nigrum berries as toxic. I am not the first to conclude this; Dunal (1813) made exactly the same argument 200 years ago in France. Displaying the fear-mongering suspension of logic that often accompanies the discussion of black nightshade berries (and wild foods in general), one of Dunal’s critics made a strident but worthless effort to discredit him by pointing out that the raw leaves have caused poisonings, stating that this “places beyond doubt the often contested toxic properties” of S. nigrum (Tardieu and Roussin, 1875, p. 925, translation mine). Of course, this has nothing to do with the berries. Interestingly, in French, S. nigrum and Atropa belladonna also share common names, and the idea that S. nigrum berries are extremely toxic is still deeply entrenched in France today. As in the English sources, older accounts of black nightshade poisonings in France are highly suspect, such as a case reported by Dufeillay (1838), in which the poisoned children described the berries as red.

The confusion between Atropa belladonna and Solanum nigrum is a problem that has long been recognized in the English-speaking countries as well. In a medical treatise on treating cases of poisoning, Murrell (1884, p. 111) says that S. nigrum is often mistaken for belladonna, adding, “Medical witnesses and coroners often wrong on this point.” In A Manual of Toxicology, John James Reese (1874, p. 450) states that

“There is great discrepancy among authorities about the poisonous properties of the above two species of Solanum [dulcamara and nigrum]. . . . Some have supposed that the cases of poisoning that have been ascribed to the two species were, in reality, to be accredited to the Deadly Nightshade (belladonna), which had been mistaken for the others.”

The following anecdote shows that the confusion has gone both ways:

“Solanum Nigrum has often been mistaken for Belladonna. A physician in Ohio confidently said to me, that Belladonna grew plentifully in every part of his county, and upon my questioning the accuracy of his statement, he produced a very fine specimen of Solanum Nigrum, saying, ‘If that is not Belladonna, what is it?’”

—Hoyt, 1874, p. 374

Indeed, the poisoning symptoms described in the old accounts usually suggest atropine poisoning rather than that of solanine. The fact that this myth originated in Europe, the primary natural range of belladonna, and has persisted most tenaciously there, lends further support to this conclusion. In contradistinction to the case with S. nigrum, the medical literature contains hundreds of cases of poisoning by Atropa belladonna berries. These cases are easily found and consistent in their described symptoms, and many of them occur quite recently. When you consider that S. nigrum is a far more common and widespread plant, eaten regularly around the world, there should be millions of such cases if it were equally poisonous. This is perhaps an appropriate place to point out another obvious fact: myths of toxicity are commonplace (in fact, I’d argue that they are a universal feature of human culture) while myths of edibility are exceedingly rare, since they are soon discredited.

People have an amazing ability to make our observations coincide with a preconceived belief (see Don’t Make it Fit, p. 33). In 1978, a red panda escaped from a zoo in Holland. Local newspapers informed the public, in hopes that the animal could be recaptured, but by this time, the panda had already been found dead near the zoo. Yet over a hundred sightings of the panda were reported, all of which occurred after the animal was dead (Feder, 1996). These people weren’t reporting the panda because they had seen it; they were seeing the panda because it had been reported. Similarly, it seems that reports of poisoning from black nightshade berries occurred because the plant was believed to be toxic, rather than the converse.

The black nightshade is not the only European plant to be subject to a toxicity myth of such stark contrast to reality. As surprising as it sounds, the parsnip Pastinaca sativa, the very same plant that is available in markets and grocery stores all across the northern hemisphere, which has been grown for thousands of years for its esculent roots, is widely reported in wildflower books to be deadly poisonous. This myth, like the black nightshade myth, probably arose as a way of keeping people from collecting the plant in the wild and confusing it with toxic relatives.

By the late 1800s, at least in the United States, some authorities began to cautiously challenge the myth. Behr (1889, p. 201) says, “It is not poisonous in California, at least under ordinary circumstances. The same species is common in Europe, where it is considered poisonous.” In 1905, Botany professor Charles Bessey wrote a letter to American Botanist regarding this inversion of thought:

“[This] reminds me of an incident which occurred in my class in Botany nearly thirty five years ago. I was lecturing on the properties of the plants constituting the Solanaceae, and, as a matter of course, said that the berries of the black nightshade (Solanum nigrum) were poisonous. A young fellow from Fort Dodge, Iowa, spoke up and said that the people in his neighborhood made them into pies, preserves, etc. and ate freely of them. I answered him, as became a professor of botany, by saying that as it was well known that black nightshade berries are poisonous, the student must have been mistaken. . . . After a while, however, I learned that the people in central and western Iowa actually did eat black nightshade berries, and they were not poisoned either. Later, I learned the same thing in Nebraska for this species.”

Since then, the obvious fact that black nightshade berries are not deadly poisonous has been slowly and reluctantly accepted. This is often expressed with guarded language and reservation, but at other times it is stated plainly that the berries are edible and delicious. Most scholarly works since about 1960 agree that the ripe berries of the S. nigrum group are edible or at least nontoxic.

Interestingly, despite the fact that enormous numbers of ethnographic sources describe the berries being used as food, and despite the fact that legions of people willingly, gladly, and repeatedly eat them, the wild food literature has become one of the loudest voices contributing to the fear that surrounds this plant. Peterson’s field guide (1977) lists it as “poisonous,” accompanied by a skull and crossbones. Elias and Dykeman (1982) lump it with other nightshades as poisonous. Henderson (2000, p. 189) nebulously suggests an unspecified danger: “Although some nightshades actually bear edible fruit, none of them are worth the risk.” Tull (1987, p. 186) says, “ I consider the whole plant potentially deadly and leave it alone.” (Here she misleadingly cites Heiser [1969], but in that source Heiser’s discussion of black nightshade’s toxicity is poorly constructed, conjectural, and flippant—and he tells us that he made and ate a black nightshade pie!) Many other wild food books take the very reasonable position of not discussing the matter. However, I am proud to align myself with the significant minority of authors (Gibbons and Tucker, 1979; Nyerges, 1999; Couplan, 1998; Van Wyk, 2005) who unabashedly proclaim the ripe fruit edible.

Still, I wondered if, very rarely, ripe black nightshade berries contain an abnormally and dangerously high concentration of solanine. It seems possible. Put into perspective, this fact shouldn’t even be particularly alarming; virtually all edible plants contain toxic compounds. There are numerous documented poisonings from potatoes Solanum tuberosum, several of which have resulted in death (McMillan and Thompson, 1979; Bruneton, 1999; Hansen, 1925). Curly dock Rumex crispus remains a popular wild edible, despite the fact that, rather recently, a man apparently overindulged on the leaves and killed himself (Xirgu et al., 1989). Does this happen with black nightshade? With this question in mind, I sought the last reported case of poisoning (nonlethal, incidentally) by ripe black nightshade berries, which occurred in Ireland and was recorded in an article entitled, “A Case of Poisoning by Solanum nigrum” (Towers, 1953).

Here, again, is a case of name misapplication. Throughout the article, there is conclusive evidence that the plant that was actually responsible for this poisoning was Atropa belladonna. The victim’s description of the plant and its berries strongly suggests belladonna, and is scarcely compatible with the characteristics of S. nigrum. The symptoms described clearly fit those associated with atropine (the primary toxin in belladonna) rather than solanine (the toxin found in unripe black nightshade berries). I was prepared to carefully advance this argument, but fortunately our good Dr. Towers does this himself—unwittingly testifying convincingly against his own conclusions. He attests (p. 79), “Having thus reviewed the pharmacology of atropine, it is possible to see that this case under discussion shows most of the classical features associated with the drug.” However, atropine is not found in S. nigrum; it is commercially extracted from Atropa belladonna, from which its name is derived. Towers apparently was unaware of this. He clearly writes under the assumption that what is true of one of these nightshade is also applicable to the other. The prevalence of this irresponsible attitude makes careless investigation of this plant no surprise. Indeed, the two-page commentary following the clinical notes mentions S. nigrum only once, in the first sentence. Amazingly, thereafter, the text refers only to belladonna and atropine. Towers concludes (p. 80) by stating that the victim’s symptoms “fit in with the classical features of poisoning by atropine caused by eating berries of the deadly nightshade type.” The name “deadly nightshade” is properly applied to belladonna, not S. nigrum (although it is often mistakenly applied), and of the two species, only belladonna contains atropine. By this point, his article has quietly transformed into “a case of poisoning by Atropa belladonna”—which should have been its title.

Through an extensive search of literary sources and correspondence with experts (including Jennifer Edmonds, probably the world’s leading authority on black nightshades), I have been unable to locate a single credible, documented case of poisoning from the ripe berries of any member of the S. nigrum complex. There is simply no basis for the contention that they are toxic.

The Second Myth: Black Nightshade Greens

As well documented as black nightshade berries are as a food source, the greens are even better documented. In fact, they are perhaps the most commonly eaten wild greens in the world. Black nightshade greens are regularly consumed in virtually every tropical and subtropical country on Earth, as well as occasionally in the temperate zones. Again, European and North American literature often calls these greens poisonous or deadly, but authors from the tropics hold a completely different attitude. Consider this:

“The tender shoots, young leaves and unripe green fruits are eaten as a vegetable, raw, cooked or steamed (for 510 minutes), alone or in combination with other vegetables. . . . S. americanum is used as a green vegetable throughout South-East Asia and the green fruits can be bought in the local markets. It is common in the vegetable assortment of large supermarkets. . . . Being a common crop of home gardens and a common weed of cultivation, its importance is considerable.”

—Siemonsma and Pilvek, 1993, p. 253

These authors conclude their account by suggesting that black nightshade should receive more research attention as a food crop. Nowhere in their rather lengthy treatment of this plant do they even mention any concern over toxicity. And note their repeated mentioning of the green fruits as food. (Be aware, however, that analyses have clearly shown the green fruit of at least some species to contain high levels of solanine. I advise against eating them.)

Chopra et al. (1965, p. 670) tell us, “The leaves and tender shoots are boiled in the same way as spinach and are eaten in many parts of India.” The young greens are eaten in Vietnam (Tanaka and Ke, 2007), Nepal (Manandhar, 2002), and China (Hu, 2005). Couplan (1998) says that black nightshade greens are the most popular vegetable in Madagascar; he says (pers. comm., 2009) that they are eaten at “almost every meal.” In three villages in Tanzania, Fleuret (1979) found black nightshade to be the second most commonly eaten wild green—only amaranth was eaten more. The greens were also sold in local markets. Purseglove (1968, p. 65) says that S. nigrum “is extensively used as a pot-herb in Africa and Asia, in spite of the fact that it is reputed to be poisonous in Europe.” Heiser (1969) found the greens regularly for sale in vegetable markets in Guatemala. Edmonds and Chweya (1997, p. 56) summarize, “Leaves and tender shoots are widely used as vegetables throughout the world . . . All the species [of black nightshade] are used as pot-herbs or leaf/stem vegetables more or less throughout their respective ranges in Africa, Asia, Malesia and the Americas.” They record the greens being consumed in Guatemala, Mauritius, Hawaii, Papua New Guinea, the Seychelles, Australia, Greece, and fourteen African countries. Black nightshade greens are eaten so frequently and widely that documenting it in this way is as superfluous as documenting the edibility of onions.

Looking to uphold the Western notion that this plant is deadly poisonous, some suggest that the edibility of tropical forms differs from ours. There is nothing to support this idea. The most widespread black nightshade of the Old and New World tropics is S. americanum (Edmonds and Chweya, 1997), but this species is also widespread in the United States. Black nightshade was said to be “the most relished potherb” of the Cherokee (Witthoft, 1947). Couplan (1998) reports it being eaten in southern Europe. In Wisconsin, Minnesota, and surely elsewhere in the United States, black nightshade greens are actively sought and regularly eaten by Hmong immigrants.

But some Americans desperately want us to disbelieve this plant’s edibility. Based on her interpretation of one anecdotal account, Fackelmann (1993) conjectures that people who eat black nightshade greens must first undergo a lengthy process of building up a tolerance to solanine—otherwise they will be poisoned. Although she provides no scientific evidence to support this specious and ridiculous claim, it has been widely accepted as fact. Fackelmann makes it sound as if only a few obscure, impoverished cultures eat this vegetable, when in fact it is a common food for hundreds of millions of people in dozens of countries, sold in grocery stores and produce markets. The tone of her article is condescending and ethnocentric. I know several Americans, including myself, who have eaten these greens safely without building up a tolerance. This doesn’t mean that black nightshade greens can be used without caution; they sometimes contain the toxin solanine (Frohne and Pfander, 2005). For guidelines on their safe use, see the preparation section on pages 390–392.

Harvest and Preparation

Berries: Black nightshade berries are delicious, abundant, widespread, and easy to harvest. Only eat the ripe berries, which turn juicy and dark purple-black. (A few species, such as S. villosum, have berries that ripen to yellow or orange, but these are not commonly found in North America.) Do not eat partially ripe berries that still contain green lines, and do not eat ripe berries if they taste bitter or unpleasant to you. As always, eat small portions your first
few times.

Don’t imagine that black nightshade berries are a substitute for blueberries or any other familiar fruit. Their flavor is most like that of ground-cherries (genus Physalis)—like fruity tomatoes. Generally, I eat the berries raw. Whenever I happen upon a plant bearing ripe fruit, I eat as many as time or the supply allows. They are excellent in salad—although being perfectly round they tend to roll off your fork, and they’re usually too small to spear with a tine. Alas, the conundrums of a forager. I also like them in tacos or burritos, where they aren’t so mobile. They are good in certain soups or pasta dishes.

Black nightshade berries are also used to make uniquely delicious fruit sauces and jams. They remind me of ground-cherries, blueberries, and tomatoes, but their tiny seeds are slightly hot, especially when cooked. (To get in the right mood for this chapter, I savored some nightshade jam from our refrigerator.) The flavor and texture can be altered by straining out the skins and seeds. They make good pies, and a few can be added to applesauce to enhance the color.

Black nightshade berries begin ripening in midsummer and continue late into the fall, often past light frosts. It is not uncommon to find flowers, unripe fruit, and ripe fruit on the plant at the same time. I have no special tricks for picking them, which I typically do while sitting comfortably beside a prolific plant. The branches droop and the fruit is often borne near the ground; in this case, wash the berries carefully. From the best plants you might get over a quart of fruit, but it will go as slowly as picking blueberries.

I was once exploring an acquaintance’s garden with him. When I found a black nightshade plant loaded with fruit and began eating them, he said, “Nightshade? My grandmother used to make nightshade sauce when I was little, but I never knew what nightshade she used.” He tasted a handful, smiled at the flavor, then confirmed, “Oh yeah, this was definitely it.” We talked a little of the sweet nightshade sauce that his grandmother in South Dakota made, which the family relished on pancakes and ice cream. He remembered this sauce fondly, saying that as a child he “wanted all he could get.”

Greens: The young, tender leafy shoots of black nightshade, before the plants have flowered, make an excellent potherb—in my opinion equal in quality to amaranth and lamb’s quarters. Gather thick, juicy shoots that stand upright, snap easily when bent, and do not need to be cut. You will find these mostly in early or mid summer. They should be boiled before being eaten. Their rich, mild flavor and soft texture leave no question as to why they are a popular vegetable in much of the world. The older growth, however, is bitter and should be avoided.

Although the greens are the most commonly eaten part of black nightshade worldwide, they contain varying amounts of the bitter toxin solanine. (Solanine is also found in tomatoes, potatoes, eggplants, bell peppers, and even cherries.) As with the ripe berries, I have been unable to find any documented cases of poisoning from eating the properly cooked young greens. Although Edmonds and Chweya (1997) report that toxic alkaloids are not present in the vegetative parts of the plant, others have reported solanine in some leaf samples (Frohne and Pfander, 2005).

The youngest, tenderest shoots are generally not bitter. As the plants age, the bitterness (and presumably, the solanine content) increases—sometimes substantially. I reiterate here that the older growth, or any greens that are distastefully bitter, should not be eaten. Marshall (2001) interviewed villagers in Kenya and found that, while black nightshade was the most favored and most commonly eaten green, they recognized and avoided those with certain subtle characteristics that denoted bitterness (older, tougher, drier stems with full-grown leaves, especially stems that spread horizontally). Marshall reported that her informants preferred it because, unlike amaranth, it could be eaten every day without making one feel sick.

The bitter quality of black nightshade greens has been overemphasized by Western authors whose attitude about the plant is irrationally negative. After all, many of our more popular greens are bitter (dandelion, chicory, escarole), toxic when raw (marsh marigold), or toxic when too old (pokeweed). When collected at the correct stage and prepared properly, black nightshade greens are not only safe to eat, but are a palatable, nutritious, and wholesome food.

When collecting black nightshade greens, follow these guidelines to avoid ingesting excessive solanine: (1) harvest only the young, tender growth, generally before the plants flower. (2) Boil them in a full pot of water for ten to fifteen minutes, drain the water, and repeat this process if any bitterness remains. (3) Do not eat oversized portions. (4) Do not eat them if you find the bitterness strong or distasteful. (5) Stick to those species which have a well-established traditional use as food. (Among North American species, this means S. americanum and S. ptychanthum.)

Some Western authors, attempting to explain away the obvious edibility of a plant that their culture erroneously believes to be poisonous, suggest that black nightshade greens are eaten regularly by hundreds of millions of people only because of their medicinal properties. It is true that this plant is traditionally considered a health tonic by many cultures, as well as a remedy for numerous ailments, including malaria, dysentery, and schistosomiasis (Gbile and Adesina, 1988). Studies have also demonstrated that these greens have antiviral, anticancer, and antiparasitic properties (Gbile and Adesina, 1988; Bose and Ghosh, 1980). However, these are secondary benefits; most people who eat these greens clearly do so because they like them and are hungry. Black nightshade greens are also extremely nutritious, providing a much appreciated rich source of proteins, amino acids, minerals, and vitamins (Edmonds and Chweya, 1997).

Some who remain afraid to try black nightshade act as if those of us who eat it are foolish and irresponsible. Meanwhile, hundreds of millions of people eat it anyway. I counter that it is irresponsible, and a bit ethnocentric, to insist on perpetuating this myth in the absence of any supporting evidence. After all, both the tomato and potato were once considered poisonous in Europe.