Carolina horsenettle

Continuing the discussion from Ground Cherry Grex:

Every time I see Carolina horsenettle I think about its possibilities. I even wonder about food and medicinal uses, not just breeding use. I know the plant is ostensibly poisonous. I put the “ostensibly” in there because of previous personal experience with “poisonous” plants that have documented ethnobotanical use and are safe to consume in reasonable quantities (and arguably typically much safer than many “non-poisonous” and widely eaten modern foods).

Any additional knowledge in the group about ethnobotanical use, contemporary use, or breeding work with this plant?

Horsenettle is very common here. My undertsanding is that horsenettle and its closest North and South American relatives are all quite close to the cultivated old world eggplants.

Here is one free paper that gives me a lot of hope that crosses would not be difficult: Agronomy | Free Full-Text | Evaluation of Advanced Backcrosses of Eggplant with Solanum elaeagnifolium Introgressions under Low N Conditions

I think I’ve seen two more papers referencing this one, at least one tried and succeeded in recreating the cross with Solanum elaeagnifolium.

Evaluation of Advanced Backcrosses of Eggplant with Solanum elaeagnifolium Introgressions under Low N Conditions

In this study, we evaluated advanced backcrosses (AB) obtained after the backcrossing for several generations of an S. melongena × S. elaeagnifolium interspecific hybrid [15] towards the recurrent S. melongena under low N conditions. The analysis of phenotypic and composition traits provides information of interest for breeding of eggplant materials with S. elaeagnifolium introgressions for cultivation under low N conditions. The high throughput genotyping of the AB individuals with the eggplant SPET platform also allowed a preliminary genome association study for the detection of QTLs of agronomic, morphological, and fruit quality traits under these conditions.


There was one eggplant introgression lecture on youtube that talked about a study to cross eggplant to it’s wild relatives. I think all worked although often through embrio rescue and many only one way with male sterile F1s. Since those 2 species come from 2 different continents I would think it’s not as simple of a cross as some of the more closely related species. it seems I accidentally crossed common eggplant with african eggplant that I had for some reason and atleast fruitset seems good. Have to open them up later to see if I have seeds as well.

These are some species believed to be closely related to Carolina horsenettle that have culinary uses and have caught my eye. I’ve read one analysis of eggplants that postulated that all of the South American relatives were relatively closely related to the South Asian eggplants, and furthermore that all North American relatives (including Carolina horsenettle) evolved from one of those South American species.

If that scenario is close to accurate, it would be very encouraging for crossing Carolina horsenettle with more edible species.

  • Solanum aethiopicum - Ethiopian Eggplant (‘pumpkin on a stick’)
  • Solanum gilo - Scarlet Eggplant/Jiló
  • Solanum melongena var. esculentum - Thai Eggplant
  • Solanum muricatum - Pepino Melon/Sweet Cucumber
  • Solanum quitoense - Naranjilla/Lulo
  • Solanum sisymbriifolium - Litchi berry/Sticky Nightshade/Red Buffalo Berry
  • Solanum torvum - Turkey Berry/Prickly Nightshade
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Pepino, naranjillo and litchi berry must be just as closely related to eggplants as tomatoes are. Based on this lecture and study in it only naranjillo made list as closeness, but outside group 3. It seems that s.torvum from group 3 did not cross with eggplant, but there was one species that from that group that crossed. Carolinian horsenettle don’t even make group 3 so it must be really distant relative to eggplants. You might want to get some sort of family tree to track down it’s close relatives. It might be that they don’t include any domesticated species and you would need some wild x wild crosses and be the one to domesticate.

There is a “family tree” in this paper which is one of my references for the closeness of relationships: Phylogeny of the Carolinense Clade of Solanum (Solanaceae) Inferred from Nuclear and Plastid DNA Sequences on JSTOR

I think this is all pretty far from the domestic tomato.

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Yes, but my point was for the other 3 species that are likely to be as closely related to eggplant as tomato is to eggplant. Same goes for carolinian horsenettle; it’s probably as closely related to eggplant as it is to tomato. That’s a nice family tree, although not much that would ring a bell, except for s.torvum and just for that lecture. Not that those latin names are so easy to remember. Is there any reference how carolinense relates to eggplants and it’s closer relatives. Just out of interest it would be nice if there were big family trees like for solaneceae and other families, and then how those families relate to others. Might be quite a big tree, but it would be interesting to track back where they separeted.

I actually don’t think the research I posted supports the possibility for those other species to be as close to eggplant as tomato, but now that I understand what you mean I will be looking for more information on those lines.

I do think it would be fun to see more of the giant Solanum genus represented, but on the other hand, I can appreciate why tomato and its close relatives don’t appear in this chart – again, I’m pretty sure there is consensus that the species I posted are much more related to eggplants in the tree of life than they are to tomatoes.

I would suggest that Solanum subgenus Leptostemonum section Melongena is probably going to have some members added or removed in light of modern genetic and molecular testing, but even so, that section of Solanum seems to generally represent some kind of close relationship.

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Yes, they probably are, but in relative terms it’s just as well. Genetics might not tell the whole story also. It might be that they have made more similar path, but are way different where it matters and are just as far removed in time as tomatoes for example. Like nautilus have barely changed when they split from common ancestor with octobuses whereas octobuses, and other groups that evolved from same ancestor, have diversified. Maybe not the best example, but it shows how there are many road life form might take.

When it comes to carolina horsenettle, sometimes it might be better to start a new path with what is likely to work than trying to reach out for something that is not realistic in regards to crossing. Being poisonous might be challenge in itself and Isuppose all closely related species are poisonous as well? Maybe there is a accesion that is not poisonous just waiting to be found, but no one is looking for it. It’s the problem with obscure plants when it is easier to just work with known species.

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We have horse nettle all over the place (no idea if it is “Carolina” or a different variety?) and I have been focusing on trying to get rid of it. Then I stumble into this topic and you’re trying to make use of its genetics… have to say I didn’t expect that.

What is the benefit of trying to breed with the horse nettle? Its ability to compete, grow, produce, and spread like a weed even when it is unwanted? Are you basically trying to gain those traits, or is there something else which I am missing?

For my part, I would be very interested in a small eggplant that self-seeds or re-sprouts from perennial roots. If it grew like that, it would be like ground cherries and creeping cucumber, part of my low-effort “snack size” veggie lineup. If something different but interesting or educational resulted, that would be okay too.


That Phylogenic Tree you linked to was EPIC!!! Thank you. Carolina Horse Nettle Is in the same section (Section melongena) as Domesticated Eggplant which is worthy enough to try breeding with. That’s where Wikipedia places them both, under section melongena.

Regardless, I think the Cross wouldn’t be edible raw and probably must be cooked. Another Question to answere is how ripe must the fruit be to be

  1. Enjoyable
  2. Safely Processable like via cooking.
  3. How ripe must it get to in order to be edible?
  4. How would you breed out those nasty thorns? And what if they Poke the fruits when blowing in the wind?

ALSO have you just tried grafting eggplants onto Caroline Horsenettle to see if they are even Graft Compatible? If it can at least past that test, (Ideally both ways, but at the very least one way) then I think it’s worth your time to cross them. Also use the Mentor Pollination technique where you mix compatible pollen with incompatible pollen together to force the flower to accept the foreign pollen.

Thought this might be interesting, here’s what PFAF says about it. No edible uses.

I have no more details to add, but I thought I might add two photos for people where horsenettle isn’t common. This time of year it’s easy to find clusters of berries growing in very adverse locations.

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Order of toxicity: unripe berries, ripe berries, leaves, stems, roots.

I think it would take alot of generations breeding to get them back to something edible. I have horse nettle here. Sheep don’t eat it. Goats don’t eat it. Nothing grazes it. I use high density rotational grazing just in part to get the sheep to trample stuff like this and knock it back.

My dad didn’t used to know what it was and he said that the goats (I grew up around dairy goats) would in certain bales in the winter go after it like candy. My sheep don’t seem to eat it in the hay. I’ve definitely not seen them go for it like candy, ever.

Online searching for toxicity of it seems to say that treatment for it is variable because the level of solanine (sp?) can be really different between plants. So I suppose that could mean you can select for the lower level plants to breed. If you could test for it in a home setting/simple lab setting (ie, not expensive equipment or testing) that would make it a whole lot easier and faster.

The berries seem much more like potato berries. I imagine alot of the seed is viable in green unripe fruits. It spreads around enough and I’ve been working on pulling/stomping/grazing/cutting it out for years. It will have plenty of berries but I only see ripe ones late fall and winter. Like now I’m seeing them ripe. For me I’d say into November or well into freezing night temps.

The berries are hard. They don’t seem appealing to eat at all. The really ripe ones only seem to dry down and shrivel up like raisins.

The grafting idea is interesting. Heck, there’s always some tomato to prune back, I’d even see if they would graft just to see.

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HMMM!!! Could it be that Frost Destroys the Toxins? Kind of how Cooking Destroys the Toxins for Eggplants? Maybe the Some Animals maybe Hinting at something here.

Maybe this is when they become more edible. Still wouldn’t risk eating too much.

Speaking of Potato Berries, the Scary part about them was some of the Poisonous ones actually Tasted Pretty Good and Sweet. Now Imagine if you somehow Made Carolina Horsenettle Taste Sweet and Not Bitter just to then end up in the Hospital for food poisoning. That’s a Scary Thought. Since both Potato Berries and Horsenettle are Solanums (Different subgenus but still solanums).
I think the simple Lab Testing may be an absolute necessity here.

Please test it out, I’d love to Confirm as well! Do it both ways, Horsenettle Scion on Tomato Rootstock and Vice Versa. Also Try Experimenting with Bridge Grafts if Possible, where you graft a Tomato onto a Potato then on the newly healed graft, graft horsenettle on it if something is incompatible. Just have fun!

I had completely forgotten about this. A while ago, as I was doing chores there was a perfect little branch with two berries on it. I tucked it in a pocket and brought it inside and it’s been hanging here since.
One thing that is interesting, these berries never seem to be damaged even when they are in the middle of a round bale. Having been cut, dried, fluffed, dried more, run through the baler, squashed into a round bale, and in varying conditions since. They aren’t squished. They aren’t moldy. Actually if anything they have quite high dry matter and low moisture, unlike a tomato. The berries seem rather fresh coming from the bale and it seems to have slowed them drying out more. They have been drying and shriveling more since they’ve been inside.
Hay is second cutting made in late August/early September. I don’t remember when I grabbed the berries… Around Thanksgiving-ish time.

I should walk the pasture and see if there is any standing with berries still to collect too.

I’m tentatively planning to grow them and see if there are changes in the gardened ones vs the wild ones. The stems are more woody and fibrous than tomatoes. I may attempt grafting just to see.

True Love Seeds has a surprising amount of diversity of eggplant relatives, I thought might be of interest/related.

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I’m not sure if this is off topic, but related to weedy and misunderstood, potentially poisonous nightshade berry plants that should be explored more for food.

We have an aggressive black nightshade weed here, they are similar to Wonder Berries and this one

Weed Gallery: Black nightshade-UC IPM

Almost everybody assumes they are poisonous. But in fact they are delicious and not toxic at all as far as some people say, though the link above says they might be to some extent.
They are very very aggressive weeds. I have collected seeds from the plants with the big tasty berries, but I need to collect more and take some photos if people are interested.


I have Found Carolina Horsenettle Fruits in March, Both Times they Stank! (REALLY BAD, Vomit Bad!), definitely not food although this could also just be because they sat on the plants all winter long. So I don’t think Frost Destroys the toxins

But what do they smell like?

I would be very interested! I’m trying to get Black Nightshade Fruits as Huge as a Beefsteak Tomato & I think it’s possible. Some people cook the leaves & eat them as Greens but I avoid it since the fruits are more interesting, unless a Black Nightshade gets Landraced/Cultivated for the leaves & bitterness reduced significantly. I think we should Start another Page on Black Nightshades Specifically rather than off topic the Carolina Horsenettle Tread (But in all relatedness, both are solanums so… hehe)

From Feb 1st. Four berries pulled from hay bales and inside for a while, now bone dry and shriveled up. The one next to the dime was freshly grabbed from a bale. Part dried but still plenty of moisture to it. Very firm, like a hard carmel if that makes sense. Now 3/28 and I don’t know if I could pick the newer berry from the older ones.

Sheep and everything has me busy. (Last week of lambing! Light at the end of the tunnel!) But I’m trying to get out and walk the pasture to see if I can find any berries still on the plant in the field. Be interesting to see how they look compared to ones in bales. Plus keep the seed from growing in my pasture!

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