Identifing and foraging beach rose | Edible flowers and rosehips

Latin name: Rosa rugosa
Common names: beach rose, wrinkled rose, Asian beach rose, seaside rose, coastal rose
Seasons: Spring (flowers), late summer and fall (fruit/hips)
Edible: Yes, fruit and flower petals (but not seeds)
Medicinal: Immune support, anti-inflammatory, anti-aging
Nutritional: Vitamin C, A, E, K, B 1-3, polyphenols

Identification difficulty: Beginner

Roses are one of humankind's oldest plant allies and their use is also among the most widespread. Ancient Egyptians, Chinese and Persians used parts of roses as topical and internal medicine and even as offerings to royalty or the Gods, starting as much as 5000 years ago. And when it comes to rose hips--the fruit of the rose (more on that later)--they were consumed as a food by prehistoric people of all temperate climates, dating back at least 10,000 years. Roses are still being used as a food today, albeit in a much-reduced fashion, primarily as an ingredient in herbal teas. 

And when we get to the greater rose family (Rosaceae), many of our planet's most valuable food crops are members. Did you know that apples, pears, plums, apricots, peaches, blackberries, raspberries, juneberries, and even almonds are all part of the greater rose family? Well, now you do!

Beach rose bud

Beach rose quick history

The beach rose, Rosa rugosa, is unlike any other rose species you'll encounter in North America. That's because the beach rose isn't from around here. Native to Japan and China, the beach rose was imported to America in the early 1900s (perhaps as early as 1908), to combat erosion along our Atlantic coastline. Possibly introduced broadly to the States in either the 1858 or 1874 World's Fairs (both held in Philadelphia), this plant would be imported wholesale as an erosion solution during the 1920s. Many will argue that beach rose has become "invasive", but I would claim that to be a misunderstanding in the United States, at least. (I don't know enough about other countries to say one way or another for them). Beach rose was heavily planted as erosion control along the coasts of New England, the Mid-Atlantic states, down as far as Virginia, and up into Canada in Quebec, New Foundland, Labrador, Nova Scotia and P.E.I.  Further, it was planted as an ornamental in Ontario, Canada, and the northern mid-west and great lakes states of the U.S.A. 

Beach rose forms dense mats on coastal sand dunes, earning a reputation as an invasive species

As an invasive species

Beach rose has gotten a lot of bad rap in the past few decades (since around the late 1980s) as an invasive species. Today it can be found throughout Europe, the above-mentioned parts of North America, Central America, northern South America, and much of S.E. Asia. For this reason, it's considered invasive in many U.S. states. But here's the thing: I grew up in New York, New Jersey and many states in New England, where beach rose is often planted as an ornamental plant, and I've only ever seen it become a monoculture in unnatural, man-made or man-influenced environment. 

Not only have I never seen it spreading uncontrollably out of people's gardens, I've never seen it in the wild, outside of sand dunes. While sand dunes are natural, the dunes of New England are highly human-influenced and maintained by dumping non-native sands to preserve the beaches that are so crucial for tourism. (For what it's worth, I have no issue with man-made beach interference, but I do think it needs to be mentioned. In fact, beach rose is considered endangered in its native country of China--which doesn't imply invasive behavior. 

Identifying beach rose

Ok, coming down off my soapbox, let's get to what I'm sure y'all are here for: How to identify beach roses and how to use them in the kitchen or as medicine. The good news is that beach rose is arguably the very easiest rose species to identify.

Beach rose distribution, environment and growth patterns

Beach roses are found in the New England and Mid-Atlantic states south to Virginia and west to Missouri, and north into the eastern Canadian provinces, west to Ontario. It can also be found in Washington, Oregon, Alaska and northern California. It's spread broadly throughout South and Central America in recent years, including Mexico, Cuba, Panama, Argentina, Chile, Boliva, Peru, Columbia and Venezuela, among others. 

Rosa rugosa can grow in many environments, including both acidic and alkaline soils, in full sun to partial shade, inland or costal (it can survive salt spray), and in nutrient-rich or nutrient-poor soils. It can only survive in moderate temperatures but can survive in lower moisture environments--not in semi-arid or deserts though.  

On sandy soil, beach rose grows low and dense,
like a ground cover

Where the soil is rich, water is plentiful, and sunlight is dappled, it will grow into an impressive bush, as much as 6' high and over 10' wide, though about half that is more common. When the soil is poor, sandy or loamy, the available moisture is rich with salt, winds are strong, and sun is bright and there's no shade, beach rose grows low to the ground (rarely more than 18" high), and spreads into dense matts of overlapping plants. 

Leaf, thorn and stem features

The stems of beach rose are green and bendable for generally about the first year. They also don't develop thorns until after the first year. As the stems age they become a brown/red shade, then brown/grey and eventually a charcoal grey. The thorns also become denser. Unlike the hooked or curved thorns of cultivated roses, beach rose thorns are straight or conical. The thorns grow from all sides of the stem. 

Thorn features

Oddly pinnately compound leaves
(9 leaflets for this example)

Beach roses have oddly pinnately compound leaves that have 5 to 9 leaflets, with the overwhelming majority being 7. Compound leaves mean that the leaf is actually made up of multiple "leaflets" that might each appear to be individual leaves. Oddly compound leaves feature parallel pairs and one extra leaflet that sticks out at the end, opposite the leaf stalk.  

Unlike the leaves for cultivated roses, tea roses and native wild roses, which appear basically flat, smooth and glossy, the veins on beach rose leaflets are deeply creased, creating a textured, almost crinkled effect for the whole leaf. Beach rose leaflets are lime green when young or old and dark olive when mature and healthy. Leaflets do NOT have thorns on their back or the back of their veins. As with all roses, beach rose leaflets have serrated edges. 

Flower, fruit and seed features

White variant

Beach rose flowers range from white to deep magenta, even burgundy, but are most commonly a mid-tone bubble gum or "Barbie" pink. There are also specially bred, cultivated variations that are red, baby pink or even yellow. Flowers can grow individually but are more often found in clusters. The bloom is around 2" in diameter. Wild varieties generally have 5 thin, fragile petals but often loose some to strong coastal winds. Cultivated varieties often have more petals or even double rows of petals; wild and cultivated varieties might hybridize, so it's not unheard of to find 7-10 petal variants in the "wild". The petals surround a circular cluster of bright yellow stamens and feature a deep central crease that ends in either a point that sticks out past the main edge of the petal or a notch that dips into it. The flower calyxes are unobtrusively smaller than the blooms.

Fruit ripening progression

Fully ripe rose hip fruits

The fruits, called hips, start out hard and green, then yellow and slowly ripen to orange, dappled red and eventually fully red and waxy looking or even almost translucent. They generally aren't truly ripe until they are red and soft, though you can also ripen them off the plant. While the hips of native and cultivated roses are smaller than a pea, beach roses have large, fleshy fruits that are much easier to harvest and process. Each is generally around the diameter of a nickel to a quarter (3/4 to 1.25") at its widest point. Some plants have fruit that's wide than long and sometimes it's the opposite. The sepals form an elongated "crown" on the bottom of each fruit, away from the stem. The crown starts out as light green and soft but will turn brown and eventually dried out when the fruit ripens. The crown is essential for safe identification.  

The sepals that form an elongated "crown" or perhaps tentacles that come out of the bottom of the fruit are essential for identification.

Beach roses flower from mid spring to mid summer and start fruiting from late spring onward, so you can often expect to find plants with both flowers and fruits simultaneously, helping to aid your identification. 

Look-a-like plants

Small fruit of the common wild rose,
Rosa virginiana

Alright, so I think this is a first for me, but honestly, I don't think that beach rose has any American look-a-like plants, except for other roses (which are edible). And honestly, fruit size pretty much rules those out. Please remember, my blog is American and I don't know enough about other countries to be 100% sure of look-a-likes there. 

Here are the key things to look out for to ensure you are ruling out potentially dangerous plants:

• Thorns on the stems but not on leaves
• Leaves are oddly pinnately compound
• Fruit has a bottom "crown" of elongated sepals 
• 2" diameter blooms with a single row of 5-petals surrounding yellow sepals

You might want to look at pictures of hawthorn flowers and fruit which do look similar. While hawthorn is a tree, young specimens might resemble a shrub. Hawthorn flowers and fruit are edible and the plant is part of the rose family.

Continue reading for eating, foraging, nutrition, medical benefits and topical uses for beach roses.

Edible Giant Ragweed Foraging and Identification

Latin name: Ambrosia trifida & Ambrosia trifida var texana 
Common name: Giant ragweed & Texas giant ragweed 
Season: Early spring through early fall
Edible: Yes, seeds, greens, buds, and flowers. But see potential toxicity warning below
Flavor: Fair 
Medicinal: Possible
Nutritional: protein and fats for the seeds, presumably standard green nutritional values for greens
See below for information regarding allergies and potential toxicity 

Identification difficulty: Novice when mature, Intermediate when young

Identification note: If you live in a region where giant hogweed, Heracleum mantegazzianum, is known to grow, pay especial attention to the look-a-likes section of this article. Giant hogweed is deadly poisonous and can cause blindness and chemical-like burns from simple contact. 

Please note, I am honestly not sure if the images I have here are for giant ragweed, A. trifida, or its subspecies, the Texas giant ragweed, A. trifida var. texana. The share edibility and identification features. 

Giant ragweed distribution

Giant ragweed is a native North American plant found throughout most of southern Canada, 47 of the 48 continental United States (comically avoiding Nevada), and southern and central Mexico. It has been introduced and become invasive throughout much of Europe, parts of the Middle East, and east, southeast and northeast Asia. As always, my guides are intended only for readers in the United States, as I don't know about look-a-like species in other parts of the world. 

Giant ragweed and allergies

Ragweed pollen is second only to mold when it comes to the likelihood of triggering allergies in humans. Ragweed is generally the true cause of so-called "hay fever" in the late summer and fall, though this often gets attributed to goldenrod, or, well, hay. 

For anyone who has a high sensitivity to pollen-related allergies, asthma or any other raspatory disorder, I would advice avoiding this plant when it's flowering, including not consuming ragweed flowers. While it is possible that consuming ragweed pollen might help build immunity, there is no clear evidence backing that AND it's pretty much impossible to gather and use without inhaling a significant amount of pollen. Marie Viljoen of Gardenista recommends wearing a mask. I recommend foraging it before it begins pollination, so in late May, June or early July. 

In large part due to climate change, the range of introduced ragweed is spreading rapidly. Ragweed also produces more pollen in warmer years, increasing the allergy risk with global warming. 

Do an allergy test before consumption

Despite the high incidence of allergies to the pollen, what we know about the greens indicates they are safe for most people. Still, I would definitely start with a small amount at first and if you have ragweed pollen allergies, even do an allergen test on the greens before eating them. An allergen test involves grinding up a few leaves into a paste using a mortar and pestle. Then rub the paste over the inside of your elbow. Allow to sit for around 2 minutes then rinse off. Wait up to 5 days and see if the area develops any reaction, such as redness, blistering or itch. If you see any reaction, do not eat this plant, even in small amounts. Of course, if you have a severe reaction, even to a skin test, consider seeking out immediate medical attention. 

Giant ragweed history as a food crop

Seeds of a cultivated form of giant ragweed have been found in ancient sites of the Native Peoples of the Americas, most notably those of the southwest and plains states, including the Cheyenne, the Sioux and the Osage. 

These seeds are much larger than any that grow naturally, indicating that giant ragweed was important enough to prioritize size (and potentially nutritional content) when choosing which strains to cultivate. Despite some sources claiming that giant ragweed was merely ritual or medicinal in use, this focus on size would indicate food use. Other sources agree that giant ragweed was most likely cultivated for its seeds as a source of protein and fat. This cultivation goes back at least 2000 years, but ends between 500-800 years ago, most likely due to the spread of maize from the south. Maize (the precursor to corn) naturally grows larger and, while it lacks in protein and fat, it is higher in caloric value, due to being primarily carbohydrates. Additionally, the calories in maize are easier to utilize, since they do not require dehulling or winnowing.

Despite significant evidence of the seeds being eaten and even cultivated for larger yields, there is scant evidence that the greens were eaten, though many native tribes used them medicinally and/or ritualistically. Despite no clear history of human consumption, the foliage is desirable for most livestock.

Ragweed seeds make up an important part of the diet of game birds and migratory birds, small mammals and even larger mammals like deer.

Giant ragweed identification (mature plants)

A massive stand of giant ragweed, showing average mid-summer height of 4-6 feet

Plant size and location

• Usually by early summer, June through July, giant ragweed is best identified by it's impressive fully-grown size, when the plants will be anywhere from 5' - 7' tall. However, they start out small, almost like a groundcover plant. 
• Plants grow in a variety of conditions, including nearly full shade, but favor full or partial sun. Giant ragweed is a ruderal species, which means it likes to move in on disturbed soil. This means it's often found in creek bottoms and similar areas, but will also pop up where land has recently been cleared, such as for farming or construction. 

Depending on growing conditions and plant age, giant ragweed leaves vary greatly.

Leaf shape, size and texture

• Giant ragweed leaves are always large to extra large in size for the size of the plant. Even when the plant is young, they will be over 4" long and 3" wide. When the plant is mature they will be between 8" and 12" long and 8" and 10" wide. 
• Giant ragweed leaves are deeply lobbed. When young, the plants may only have 3 lobes but as they mature they should have 5, though sometimes the leaves at the top will still only have 3. 
• Giant ragweed leaves have a lot of variety in how they are lobed. Sometimes they resemble maple leaves, with the lobs going down about half the length of the leaf. Other times the lobes will cut much deeper, cutting almost to the center of the leaf. 
• The back of the leaves are silvery green in color and the underside of the leaf veins are covered in tiny hairs. This makes the leaf feel almost sandpapery underneath, its also why these greens should probably always be eaten cooked. The fine hairs can irritate the throat. 

Tiny hairs line the undersides of leaf veins. 

During the earlies spring weeks (March 7 here)
Giant ragweed leaves will look significantly different from the mature ones

Very early giant ragweed leaves

Identification of young plants (March - April)

Giant ragweed doesn't really start to bolt until mid to late spring, reaching around 3' - 4' tall by mid-April through May here in Texas. Before that, it stays small (under a foot) throughout March and early April. It even starts out looking like a groundcover. 

Very early in the season, the end of February through the first week of March here in north Texas, not only will giant ragweed be low to the ground, it will also almost never have any 5 lobed leaves, they will all be 3-lobed or even 2-lobed "mitten" shaped. 

By the middle of March the plants, while still groundcover height, will start to primarily growth their 5-lobed, mature leaf forms. Of course, these young plants will still have some 3-lobed leaves as even mature plants retain some of those. 

Same plants on March 18, you can see they are starting to grow a number of 5-lobed leaves.

Foraging and Identifying EDIBLE black nightshade berries

Latin Name: Solanum nigrum, Solanum americanum and Solanum ptychanthum
Common Names: Black nightshade
Season: Summer through mid fall (northern states/Canada), early summer through fall and early winter (southern states/Mexico)
Edible: Yes, ripe fruit (see note about young green leaves)
Flavor: Excellent 
Medicinal and nutritional value: Undetermined, probably similar to tomatoes 

Identification difficulty: Intermediate

Warning: The plants known as "black nightshades" are in the nightshade family, which has some infamously poisonous and deadly members, including deadly nightshade, Atropa belladonna. The plants we will be discussing today are more closely related to tomatoes and eggplants, and have fruit that is edible when FULLY RIPE and cooked. Unripe fruit has been known to be deadly poisonous, especially to children. Even though we will go over how to safely identify and forage these plants, especial care should be given whenever foraging the nightshade family, and you must consult with several reliable sources regarding identification and safe consumption of these plants. As always, this blog is intended as a guide, but not the sole guide. 

Nightshade. The very name is nearly synonymous in our cultural consciousness with poison. This is odd because, unless you have an allergy, there's a good chance that you eat nightshades most every day. 

Tomatoes, potatoes, yams, eggplant, sweet and spicy peppers, these are all fruits in the nightshade family that are readily eaten in North America and Europe. Central and South American countries frequently eat even a wider variety of nightshades, including groundcherries, tomatillos, and naranjilla. In Southeast Asia one could also find goji berries among the list of commonly eaten nightshades. 

The plants we are going to talk about today are members of the genus Solanum, specifically Solanum nigrum (European black nightshade, African black nightshade or Old-World black nightshade), Solanum americanum (American black nightshade, glossy black nightshade or new-world black nightshade), and Solanum ptychanthum (Eastern black nightshade or Indian black nightshade). The three species of black nightshades are in the same genus as tomatoes, (Solanum lycopersicum), potatoes, (Solanum tuberosum), and eggplants/aubergines (Solanum melongena). 

Collectively, these plants are called black nightshades in North America, a name which encourages confusion and fear with another black-fruiting nightshade called deadly nightshade, or Atropa belladonna. In Europe, these species are sometimes known as garden huckleberries, but the name huckleberry refers to a completely different plant, related to blueberries, in North America. 

In honor of spooky season, I thought it would be fun to share this post in October. Happy Halloween, everyone!

Black nightshade caution and controversy

I'm trying to get more confident at identifying
black nightshades at this young stage so that I may 
try the cooked young leaves. 

There are many sources, including some very official ones, that will tell you that the fruit of black nightshade plants is poisonous. Many state websites state that the ripe fruit is less poisonous than the other parts of the plant, but poisonous nevertheless. Some people say they eat the ripe fruit raw, and still others say it must be cooked. 

Additionally, there are many sources which will tell you that the young leaves and stems are edible cooked and used as a pot-herb in many parts of the world. Still other sources will tell you that the plants may be edible in say, Africa, but become poisonous in North America. There is also the possibility that these nightshades might hybridize with other members of the genus Solanum, and that's why people have found poisonous leaves. . .

So what to believe? Well, I don't know everything, so I am only sharing with you here what I DO know. and that is that I have eaten the fully ripe, black berries, both completely raw and fully cooked and have suffered no ill effects. I have not eaten the young green leaves, but if I do I will let you know. I will not make any statement I have not personally tried myself. 

That said, I would be willing to try young black nightshade leaves, as I trust the sources who say they are edible, but personally I find the young plants difficult to distinguish from other, potentially poisonous nightshades. The plants are hard to tell apart before the flower buds form, and once the flower buds do form, you shouldn't be eating the leaves any longer. 

Mature old-world black nightshade plant, Solanum nigrum, growing on my own property,
portion of a woman's size 10 foot (mine) for scale.
Plant is covered in flowers and both ripe and unripe fruit. 
Photo taken north of Dallas in late May.

Mature American black nightshade, Solanum americanum, growing in one of the most disgusting alleyways in downtown Dallas TX, and absolutely loving it.
Covered in flowers and fruit (I didn't eat, given the location).
This picture was taken in mid-December.

Black nightshade identification

A special note on identification

The three "black nightshade" plants are different but have overlapping features, which makes grouping them together into one ID post rather tricky. Solanum nigrum and Solanum americanum are the most different, and Solanum ptychanthum is kind of like a mix between both features. In fact, some speculate that S. ptychanthum might be a hybrid species from intermixing between the native and introduced plants. Regardless, I will do my best to specify which features are the same and which are different between the species. 

• S. nigrum, commonly known as black nightshade or European black nightshade is native to Eurasia but has spread throughout the Americas, Australia/Indonesia/New Zealand, and parts of Africa.
• S. americanum, commonly known as American black nightshade or glossy nightshade, is native to northern South America, Central America, the southern and west-coast states of the United States, and--surprisingly--Australia. It has spread beyond it's native range and can be found throughout the Americas, and has been introduced to many warm-climate regions of the world, including the Mediterranean and many parts of Africa. 
• S. ptychanthum, or eastern black nightshade is found throughout North America and into Central America. Whether it is native or not is debatable. If it is not native, it is debatable where it originated. There is speculation that it is a hybrid species between S. nigrum and S. americanum. Despite having a larger range than S. americanum, it is less commonly encountered than either of the above species. 

In my experience in the US, S. nigrum is far and away the most abundant of the black nightshades, followed by S. americanum (most abundant on the east coast), while S. ptychanthum is quite rare. Indeed, I am not 100% sure when I have identified it and that I wasn't actually finding a weird S. nigrum. 

S. ptychanthum leaves looking a bit more lanceolate than either other black nightshade, 
but with features that resemble the other 2, including some scalloped edges like S. nigrum,
but also some smoothness at the end of the leaf, like S. americanum.

Black nightshade plant and stem features

• Black nightshade is a weedy looking plant, not much more than 2 feet tall, often much shorter, and between 8 inches and 4 feet in diameter. 
• Black nightshade is multi-branching, and will grow stretched out where conditions are less than ideal, but will grow full and bushy where it has good soil and shade. 
• Black nightshade stems are green (S. americanum) or green with red/purple branch nodes (S. ptychanthum and S. nigrum). In some cases of heavy sunlight, S. nigrum and S. ptychanthum will have fully red-purple stems.
• Black nightshade will reach its full size somewhere in late spring, but will not fruit until summer.

Purple/red blotches at the stem joints of S. nigrum; also note the unripe fruit, (which is poisonous),
with calyxes that are smaller than the berry.

Scalloped leaves on S. nigrum; S. americanum has smooth leaf edges.

Black nightshade leaf features

• Black nightshade leaves are generally diamond-shaped or pointed-egg shaped. Leaves are shorter on the side attached to the petiole (leaf stem) and elongated after the widest part of the leaf. In poor growing conditions these leaves can be more lanceolate.
• S. nigrum leaves can be quite large when mature, as large as a deck of cards. These leaves will have large scallops on the leaf edges. S. nigrum leaves are a solid bright green to emerald green with a prominent central mid-vein. Veins branch off the mid-vein and angle forward to the leaf edge. 
• S. americanum leaves are around 1/3 to 1/2 smaller, not much larger than an extra-large chicken egg, at the largest. American black nightshade leaves are emerald green and may have a "mottled" light green pattern, like a turtle's shell. S. americanum leaves have a central mid-vein, and the veins that branch off angle forward, but they don't go to the leaf edge, instead they curve into the next vein. 
• S. ptychanthum leaves have features resembling both S. nigrum and S. americanum. 
• Leaves do NOT appear as a compound leaf, which is to say, they do NOT appear like multiple leaflets growing off a central leaf stem. (More on this later)
• Most black nightshade leaves are lighter on the underside than on the top, but only slightly. The undersides are definitely not silvery or white. S. ptycanthum, however, can have purple or dark grey on the underside of the leaf.

Both S. nigrum (left) and S. americanum (right) exhibiting what
I've termed "fractal threes" leaf growth. Many nightshades grow leaves like this.

"Fractal threes" leaf growth

Many plants in the nightshade family exhibit a leaf growth that I call "fractal threes" -- I'm not sure if there is a scientific name for the term. If you look at the image directly above, you will see that leaves grow in sets of 3, which then continually add in triads. 

The image of  S. nigrum (left) has 3 large leaves, but the 2 bottom leaves have grown 2 more leaves each, making them into new sets of 3. Additionally, the  2 smaller leaves on the top set each have tiny little leaves growing, again producing sets of 3. Unfortunately, many other nightshades, including poisonous ones, also exhibit this feature. 

Another detail of the repeating patterns of threes in nightshade leaf growth,
this example is S. nigrum

Black nightshade flower features

• Black nightshade flowers have WHITE petals with yellow centers. Petals are not yellow, and especially not purple, blue, pink or burgundy. 
• Black night shade flowers have 5 petals, arranged like a traditional star--NOT a bell or tube.
• The petals of black nightshade flowers are straight at first, but eventually bend backwards, making the flower resemble a firework.
• The yellow anthers, at the center of the petal cluster, are quite prominent and stick out significantly. 
• Flowers grow in clusters, where each flower is on a stem, but the stems come together at a single point attaching to the branches. Together the flower stems bow slightly, reminding me of the ribs on an umbrella. 
• Flowers do not grow individually, nor do they grow in a line

Focus on the calyxes

Black nightshade calyx features

The calyx is a "whorl" or "crown" of sepals (flower parts) after the flower has seemingly died away. The calyx is most often green and will resemble a leaf formation to the untrained eye. The calyx appears on top of the fruit, where the fruit stem attaches. 

• Black nightshade berries have 5-part calyxes that are SMALLER than the diameter of the berry, and curve backwards towards the fruit stem. 
• The calyx looks like leaves forming a crown at the top of the berry.
• Black nightshade calyxes are green/dark green and not purple or reddish
• Calyxes are rounded on the ends, or come to soft points; they do not come to long, sharp points that look like daggers or claws.

S. nigrum fruit showing green fruit, partially ripe red/green fruit and 
fully ripe black fruit. Only the ripe fruit should be eaten.

Black nightshade fruit features

• Black nightshade fruits in summer and fall, into winter in the Southern United States. The plant will frequently have both flowers and fruit on it at the same time, helping with identification. 

• 

  Unripe fruit, which is poisonous, should not be eaten

  Black nightshade fruits are green when unripe and black* when ripe.
• Fruit ripens from green to dark green to purple-green to black. It never has a yellow, orange or red phase. If you find fruit in these colors you have the wrong plant.
• Fruit is small, slightly smaller than a pea (1cm/.4 of an inch) for S. americanum and S. ptychanthum, and slightly larger than a pea for S. nigrum. When green, fruit is the size of a pencil eraser. 
• Berries are shiny/glossy for S. americanum, and matte or dull for the other two species of black nightshade.
• Berries grow in clusters, NOT INDIVIDUALLY. The clusters hang from fruit stems, all of which come together at one point. The fruit also does not grow in a line. 
• Ripe black nightshade fruit are filled with tiny seeds that surround a central core (rather like a tiny tomato). Between the seeds the flesh is juicy and translucent, like a grape but softer and purple. 

* Some varieties produce reddish-orange fruits, but these do not grow in North America, and should not be eaten if found unless you trust a local expert to identify them for you. 

Very young black nightshade

Very young black nightshade leaves are edible, but resemble far too many other members of the nightshade family, including poisonous or deadly species. I currently avoid young nightshades and recommend the same for anyone who isn't very experienced.