American Black Nightshade (Solanum ptychanthum)

I have some questions about the wild black nightshade that grows throughout eastern North America. In my part of Ohio, the species Solanum ptychanthum is the most common species of black nightshade. Unlike Solanum nigrum and Solanum Americanum, the undersides of the leaves are black. The small, pea-sided black berries are dull and not shiny. The fruits grow in clusters of about six and the calyx does not cover the fruit. Where I live, I often find them sprouting as weeds in my garden along with lamb's quarters (Chenopodium album), amaranth (Amaranthus hybridus, A. blitum), purslane (Portulaca oleracea), yellow woodsorrel (Oxalis stricta), and prostrate spurge (Euphorbia maculata). I have found that all of these plants, except spurge, are edible. I have even saved the seeds from amaranth and lamb's quarters and planted them intentionally in the garden. Nevertheless, I have never been able to find enough information on the edibility of American black nightshade, Solanum ptychanthum. Green Deane has an article explaining how to eat southern black nightshade (Solanum americanum), but his species is different from the one that grows throughout most of eastern North America in temperate climates. http://www.eattheweeds.com/american-nightshade-a-much-maligned-edible/
https://www.youtube.com/watch?v=6n_fP1znhBs
I have already tried eating small quantities of the fully ripe berries of Solanum ptychanthum with no ill effects; however, when I ate larger quanities of the plant, I got indigestion and nausea the next morning. It is possible I accidentally ate underripe berries, but I still am not sure. For related Solanum nigrum and Solanum americanum, the berries can only be eaten once they are fully ripe. In my experience, when I let a black nightshade (Solanum ptychantum) plant grow to maturity in my garden, it sprawled two to three feet wide and yielded about 3/4 a cup of berries at a time.
I am most curious about the young greens though. I have heard reports that the young greens of the related Solanum nigrum and Solanum americanum can be eaten when cooked properly, but I cannot find any information on the preparation of nightshade greens for Solanum ptychanthum. It is possible that the very young green can be eaten after lightly sauteing them or boiling them in two changes of water, but I have not tried this not do I have the desire to try this without prior confirmation. I have not taken pictures of the plants growing in my yard yet, but until then, I have included images from Wikimedia Commons for identification.

I wasn't aware that leaves from any nightshade could be eaten. Where did you read about eating black nightshade? Not to say none can be eaten, just all the ones I know of are poisonous to some degree.
Thanks,
Daniel

I mainly heard about the edibility of Solanum nigrum and Solanum americanum from a foraging guide by Green Deane:

http://www.eattheweeds.com/american-nightshade-a-much-maligned-edible/

Here's a video:

https://m.youtube.com/watch?v=6n_fP1znhBs

There are also entries on pfaf.org for Solanum nigrum and Solanum americanum:

https://pfaf.org/user/plant.aspx?LatinName=Solanum+nigrum

https://pfaf.org/user/Plant.aspx?LatinName=Solanum+americanum

I can't find as much information about Solanum ptychanthum though. I usually eat only small quantities of S. ptychanthum at once. The unripe berries from all the prior listed species of nightshade are poisonous.

There are also several inedible species of nightshade that grow in North America. The two that come to mind are Solanum carolinense (Carolina horsenettle) and Solanum dulcamara (bittersweet nightshade). S. carolinense has large inedible cherry tomato size fruits that turn yellow when ripe. The plant is a perennial and is covered in distinctive spines. S. dulcamara has purple flowers with bright yellow anthers. It produces small inedible red berries when ripe. Here are some illustrations of the plants I found from Wikipedia:

I can highly recommend you get any of Samuel Thayer's books on wild edibles.  In this particular case you want Nature's Garden ( https://amzn.to/2LHaEeK )  That is the book in which he cover black nightshade, and covers it quite thoroughly too.)  He even notes that S. ptychanthum is the variety that abounds in his area.  He only writes about edibles he has extensive personal experience with, part of why he is widely recognized as an authority on wild edibles.  All his books set a whole new level of excellence!

In his treatment of the plant he covers why he believes there is a persistent belief that black nightshade is poisonous in western cultures despite that fact that it is probably one of the most widely eaten wild food in the world, the greens being the part most often eaten!  I would strongly recommend getting the book and reading the entire section.  I was going to copy out the section that most directly address harvest and preparation, but on thinking about it, that would be violating the authors rights, and I very much respect and support what he does.  Instead I'll just summarize my take away from it.  Harvest the young tender parts of the plant, avoid anything old, tough, or bitter.  Boil it in a pot of water for 10 to 15 minutes and drain, repeat if needed to remove bitterness.  (Personally I have never needed to do multiple boilings.)  Don't eat massive portions at once and stay with species well established for food use such as S. americanum and S. ptychanthum.

I do have a lot of this growing in my green house beds and have decided to let it grow this year since it is a nice edible that plants itself with any work from me while providing greens and berries to eat.

As I have noted earlier, this plant (S. ptychanthum) frequently sprouts as a weed in my garden, so I'm rarely short of young plants. I'll follow this procedure to cook the young nightshade greens next time I find them in my garden. I'll also consider looking for the book you mentioned.

Now I'm intrigued. I'd take anything Samuel Thayer says to the bank. Some research is in order.

Daniel Kaplan wrote:I wasn't aware that leaves from any nightshade could be eaten. Where did you read about eating black nightshade? Not to say none can be eaten, just all the ones I know of are poisonous to some degree.
Thanks,
Daniel

I know of one: a West African vegetable called gbogname (Solanum macrocarpon) Seeds sometimes sold under the name "spinach eggplant."

Here are some photos of American Black Nightshade (Solanum ptychanthum) from my garden: