Friday, October 4, 2024

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
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.