Hi all. As you've seen with some of my other posts, I like to review and condense information on entire plant families at a time whenever one catches my attention. In this case, yams led me to potatoes, which led me to Solanums in general. So here I am, on the heels of another inspirational reverie, taking a look at all the info I can find on the Solanum family. Keep in mind I haven't grown or eaten most of the species in this family, so flavor descriptions are usually second-hand and may be off from what you've tasted: correct me whenever necessary.
This list is no-doubt incomplete, as there are many lesser-known and sometimes downright obscure species that are considered apt for human consumption, and sometimes several minor species are glossed over and/or condensed under a single banner. All contributions to the post are appreciated, from species names to culinary qualities.
To start, the genus Solanum proper, and what better species than the quintessential Solanum: the Eggplant (S. melongena). Eaten cooked, it has a thick (some describe it as "spongey" or "meaty") texture, and is good in savory dishes. I'm not sure how to describe the flavor, but I guess I would consider it somewhat starchy... It's been a while since I've had fried eggplant. There are bitter components in the fruit (mainly saponins), and their concentration is highly variable, with some varieties being quite bitter (and benefitting from a rinsing process prior to cooking), and some having no discernible bitterness. Said bitterness is not a toxicity concern unless you eat it raw. Additional species include the Ethiopian Eggplant (S. aethiopicum), which includes types grown for their edible leaves and types grown for their edible fruits (Scarlet Eggplant - synonym S. gilo), as well as the Turkeyberry (S. torvum), an edible yet bitter-fruited species that can be toxic under some circumstances, and is better used as a perennializing disease-resistant eggplant rootstock.
Like the eggplant, the Tomato needs no introduction. A species cluster previously classified in the genus Lycopersicon (now Solanum section Lycopersicon), the main species is S. lycopersicum. Thick, juicy, acidic, of variable sweetness and with umami flavor due to glutamates. Definitely used in savory dishes and sauces. There are several additional wild species that are closely related to the domestic stock, have similar culinary traits and can be crossbred without too much difficulty. If looking into wild tomatoes for consumption or crossbreeding, pay close attention to species and look for reputable sources, as some species can be toxic, and some dangerous Solanums bear the "Wild Tomato" moniker without being closely related. A few short paragraphs on one man's Wild Tomato crossbreeding program (along with his other projects) can be found
here.
The Potato, that most wondrous of root crops, and the one that got me into this line of inquiry. Currently one major domestic species (Solanum tuberosum), and a very large cluster of associated wild species; I'll be using older taxonomic names to refer to the different types. I got most of my information from the Cultivariable blog (relevant links
here), they've really dug deep into the literature. Now... Onwards:
The modern domestic potatoes are descended from day-neutral Chilean Potatoes (S. t. chilotanum), which in turn are descended from tetraploid Andean types (S. t. andigena), possibly crossed with one or more wild species (S. maglia?). Other wild and domestic species have contributed heavily to the modern potato. Tetraploid Andean types are descended from High-dormancy Diploids (S. t. stenotomum), possibly crossed to a wild species. Said High-dormancy Diploids also gave rise to Low-dormancy Diploids (S. t. phureja), and to several Frost-resistant Hybrids (S. ajanhuiri, S. juzepczukii and S. curtilobum). The Frost-resistant Hybrids tend to have unsafe levels of glycoalkaloids, and usually require processing prior to consumption. The probable web of inter-species relationships is summarized neatly in this flow-chart, sourced from the aforementioned website: link
here.
There are several dozen species of Wild Potatoes (link
here), almost all of which are toxic and unsuited to human consumption. Among the readily edible species are the Mexican Cimatli types (S. cardiophyllum and S. ehrenbergii), but even these have toxic variants, so care should be taken to source better germplasm. As for the remaining species, they can be bred to reduce the glycoalkaloid content and produce edible varieties (as seen
here), but it should be considered a longer-term project; that said, even a casual breeder can do it, if they give the project time and attention.
Of peculiar interest to me is the idea of breeding potatoes for edible fruit. It's an idea that has received little to no attention, yet I think it holds potential. The fruits resemble tomatoes and eggplants to some degree, but they tend to accumulate the most toxins in the potato plant (they can be dangerous, even deadly if consumed). Nevertheless, it shouldn't be any more difficult to reduce fruit toxicity than it is to reduce tuber toxicity, as it's all the same toxins. Breeding for higher foliage toxicity (which helps to curb pests) would probably be an obstacle to fruit-breeding, as the toxins probably move more freely from foliage to fruit than they do to the tubers. Breeding for reduced foliage toxicity, on the other hand, would probably make the plant more susceptible to pests.
Luther Burbank managed to produce an edible-fruited potato by crossing to S. maglia (supposedly, but this is disputed
here). It didn't breed true (probably because it was tetraploid), and he didn't take the time to fix the trait, so the variety was lost. Link
here.
Less well-explored yet still decently popular in the garden are the fruity-flavored Solanums. The Tamarillo or Tree Tomato (Solanum betaceum) has a complex tropical fruit taste, with some lesser, savory tomato-like notes in most varieties (the red ones, particularly); the skin is distastefully bitter. The Dwarf Tamarillo (S. abutiloides) is undomesticated and more variable in quality; the best examples have tropical fruit flavor like its bigger relative (minus the savory notes), and the bitterness in the skin can be more tolerable (though peeling is often recommended anyway); seemingly good breeding potential. <<Edit: S. sibundoyense has the largest fruit of its section, with some trees bearing sweet, juicy, pleasant-tasting fruit and others bearing sour fruits; it grows well in semi-shade and might be difficult to adapt outside of its cloud-forest home.>>
The Melon Pears (Pepino, S. muricatum, and Tzimbalo, S. caripense) are not very flavorful: Pepino generally resembles melon, though some have reported good potent flavors at a certain stage of ripeness; Tzimbalo is variable, from resembling Pepino to poor, bland or bitter flavors.
Cocona (S. sessiliflorum) has been described as sour, fruity and tomatoey, good in juices, desserts and sauces; other than that vague description, it's hard to find a detailed breakdown of its flavor, or any other consistent description (żLemony Tomato?). Naranjilla/Lulo (S. quitoense) is said to have a citrusy sour taste, great in juice. Pseudolulo (S. pseudolulo) is variable in quality, with the best being sweet and similar to Naranjilla. Solanum candidum (South America), S. repandum (South Pacific) and S. lasiocarpum (Asia) are all members of this same clade, usually compared to Naranjilla in culinary qualities.
The Litchi Tomato (S. sisymbriifolium) has somewhat sweet fruit vaguely reminiscent of a seedy less-flavorful raspberry; decent, but some might find the seeds objectionable (and the plant is extremely thorny). I've grown it myself, and though not an all-time favorite, I'd grow it again.
Rarer than the fruity Solanums are the Australian Bush Tomatoes, of which nine species are considered edible (link
here). Kutjera (S. centrale) is also known as the Desert Raisin, is said to taste of caramel, with a spicy aftertaste; I couldn't tell if it was fruity or not from the descriptions, but it seems to be used mostly as a spice or in sauces for savory recipes. S. chippendalei and S. diversiflorum both have fruits with a bland, melon-flavored edible rind and a bitter inedible pulp. S. cleistogamum is sometimes seen as synonymous with S. ellipticum in the literature, but the fruits of each type are very different: the former is a contender for the sweetest, fruitiest Solanum (banana-like flavor), the latter is very bitter, though still edible. S. coactiliferum is pounded, squeezed and washed to remove bitter juices, then cooked. Other reportedly edible species are S. esuriale (which has a rubbery texture), S. orbiculatum (which is bitter), and S. gilesii.
Finally, the black sheep of the Solanum genus: Black Nightshade / Garden Huckleberries. Let me preface this section by stating the obvious: though not undisputed, there are many members in this group that are considered poisonous in some circles, even fatally so. As such, I advise that you play it safe: don't forage for these species. If you're interested in eating them, look for reputable seed sources and grow them yourself. Follow instructions, cook them into jam if required by the variety, and don't eat them underripe. Now, on to the fun bits...
There are many edible types in this species cluster, some known by species name, some without botanical ID. S. melanocerasum is generally regarded as the basic Garden Huckleberry; it's larger-fruited, should be picked dead ripe, and should be cooked. Chichiquelite may or may not be another breed in this species, but they can be eaten raw. S. scabrum is grown as a leaf crop in Africa. S. nigrum is black, S. villosum (Otricoli) is orange, and both can be eaten raw or cooked. Sunberry/Wonderberry is a strange little case... Bred by Luther Burbank, he alleged it to be a cross between S. villosum and S. guineense (ultimately named S. x burbankii); other sources dispute this, insisting it to be a type of S. nigrum or S. retroflexum... I'm inclined to believe Mr. Burbank, and so consider it a hybrid. S. x burbankii is fully edible raw (considered superior when dull-ripe instead of shiny-ripe), but it's rather insipid, like the rest of the group; it shines best when cooked into jams and pies, and is said to be exceptional when prepared thusly. Solanum opacum is said to be the sweetest member of the group, and the tastiest when raw; it is green-fruited, and sometimes said to have a slight spicy note.
Having handled the Solanum genus, now we move to the other edible Solanaceous genera...
Capsicum: the Peppers! One of the major solanaceous crops (together with tomatoes, potatoes and eggplant). Five domestic species (C. annuum, C. baccatum, C. chinense, C. frutescens, C. pubescens), many wild species, most if not all are edible and of broadly similar flavor, though the nuances of each cultivar vary, some being sweeter or fruitier (but always used in savory dishes). Piquancy varies from totally heat-free to dangerously spicy and everything in between.
Physalis: the Husk Tomatoes & Ground Cherries. The Tomatillo (P. ixocarpa) is the largest-fruited member of its genus, and has green, yellow and purple varieties; sour and mild when immature (used in Salsa Verde at this stage), and sweeter and more tomato-like as it matures. Cape Gooseberry (P. peruviana) sets the standard for the rest of the genus, juicy with a flavor vaguely reminiscent of Sweet Pineapple (some detect tomato-like flavor, but I've never felt it). Several other Ground Cherries are known from other species and without species ID, but they're broadly similar, not unlike the Cape Gooseberry; that said, they should be grown from reputable seeds, not foraged, as there are toxic species in this genus.
Physaliastrum chamaesarachoides is a Japanese species that resembles a ground cherry, and allegedly has sugary tomato-like flavor. That's all I could find on it, but I'll be growing it later this year, so I'll see firsthand what it's like.
Jaltomata contains several fruity berry-like species, and is considered a sister genus to Solanum. J. procumbens is purple-fruited and mild, not unlike the garden huckleberries. J. tlaxcala is considered one of the best in its genus, green-fruited, sweet and aromatic. <<Edit: J. weberbaueri has one of the largest fruits in the genus.>> Many other species have edible fruits, but the genus as a whole seems poorly-known. I'll be trialling J. tlaxcala, J. herrerae and J. bernardelloana this year.
Wolfberries fall under the genus Lycium, and are also known as Goji Berries. L. barbarum (Crimson Star) is the sweet berry, L. chinense (Sweet Lifeberry) is the leaf vegetable with the pepper-like berry. L. ruthenicum is the Black Goji, with the medicinal-tasting fruit. Some other species in the genus (such as L. pallidum) are considered edible, but the first three are the major players in horticulture.
And for now, that is all I could find on edible Solanaceous crops.