For a few years, I’ve been searching for an Elaegnus that would give me everything I want: cold hardiness, drought tolerance, tasty fruit, tasty seeds, thornlessness, non-invasiveness, and fertility. I haven’t been able to find one, so I thought one didn’t exist, and I would have to settle for something that wasn’t quite perfect, and try to breed it to improve it. I was eyeing goumi berry (Elaeagnus multiflora).
And then I discovered Ebbing’s silverberry.
SOMEBODY ALREADY BRED THE EXACT THING I WANT!! 
Here are my notes anout it:
Ebbing’s silverberry (Elaeagnus x ebbingei): Zone 5. Thornless! And tasty. “Elaeagnus × submacrophylla, formerly known as Elaeagnus × ebbingei, is a hybrid between E. macrophylla and E. pungens.” Both heat and drought tolerant, and a nitrogen fixer. PFAF’s Edible Shrubs book says: “The fully ripe fruit has a very rich flavor and is pleasant to taste with a slight acidity. The fruit should be deep red and very soft when it is fully ripe, otherwise it will be astringent. The flavor improves further if the fruit is stored for a day or two after being picked. The fruit ripens intermittently over a period of about six weeks from early to midspring. The seed is eaten raw and cooked. It can be eaten with the fruit though the seed case is somewhat fibrous. The taste is vaguely like peanuts.” That sounds amazing; the best out of all the various species.
Here are my notes on its two ancestors:
Broad-leafed oleaster (Elaeagnus macrophylla): Zone 7. Thornless! “The fruit of this plant is edible and has a pleasant taste, though the seed can be bitter and is often discarded. The fruit is described as having very little flesh, and the seed is wrapped in a woody case, which can be chewed for some nutritional value but is not particularly flavorful.”
Silverthorn / thorny olive (Elaeagnus pungens): Thorns. The fruits are supposed to taste like peanuts and be sour when fully ripe. They’re astringent before fully ripe. The thorns are really future branches, but ngh. That’s even worse, because I can’t cut them off. They’re long and sharp, too.
I can see why the person who bred Ebbing’s silverberry chose those two species as parents: they were probably looking for thornlessness and delicious fruits from one, plus peanut-tasting seeds from the other. And it looks like that idea succeeded.
For those who are curious, here are my notes on all the other species in the genus I’ve researched so far:
Goumi berry (Elaeagnus multiflora): Thorns. It’s drought tolerant, it isn’t invasive, and the fruit is delicious. Scarlet Sweet goumi berry has the softest thorns. PFAF’s Edible Shrubs book says, “When ripe in early to late summer, the fruit is juicy and edible, with a sweet but astringent taste somewhat similar to that of rhubarb. For the best flavor, the fruit should be very ripe, when it turns soft and bright red. The skin of the fruit is thin and fragile, making it difficult to transport, thus reducing its viability as a food crop. On young shrubs, the fruit can be eaten by birds and older shrubs may need netting if this persists. The seed is also edible and similar to a sunflower seed in taste and texture. The fruit is well hidden in the shrub and is quite difficult to harvest without damaging the plant. Goumi is an excellent companion plant: when grown in orchards, it can increase yields from the fruit trees by up to 10%. The small flowers are deliciously scented with a lilac-like smell, their aroma pervading the garden on calm days.”
Silverberry (Elaeagnus commutata): Supposed to be naturally thornless. However, it’s invasive, it’s only mildly drought tolerant, and the fruits aren’t that tasty. “They are described as having a floury, dry taste, similar to dried peas. Some sources also mention a slightly bitter taste, particularly when eating the seed.”
Russian olive (Elaeagnus angustifolia): Thorns. It’s the most drought tolerant. I’ve read in several foraging books that it tastes terrible. I’ve read somewhere the fruit is the sweetest, which seems contradictory; it’s possible it’s highly variable, but if so, I’d only want one that is simultaneously thornless and tastes really good, and that would be a challenge. You can leave it to hang on the branches through the winter, and it’ll dry out and still be edible. Other Elaeagnus species are more tart. Silk Touch / Velvet Touch Russian olive is almost thornless. It seems to be sterile: their fruits are seedless. While there are disadvantages to that, it would make it harder for them to escape and become invasive outside my yard. They don’t start from cuttings well. They are extremely astringent, even dried, so I probably don’t want it, even then.
Trebizond date (Elaeagnus orientalis): Probably thorns. PFAF: “Sweet and mealy but of better quality than the closely related E. angustifolia. Eaten fresh or made into sherbet and preserves. The fruit must be fully ripe before it can be enjoyed raw, if even slightly under-ripe it will be quite astringent.”
Autumn olive (Elaeagnus umbellata): PFAF’s Edible Shrubs book says, ”The flowers are fragrant, blooming in the spring, with a lovely warm spice smell. Japanese silverberry can grow in nutritionally poor soil and can tolerate drought and maritime exposure. The red berries are juicy and pleasantly acid.” And: “The fruit must be fully ripe to eat raw, otherwise it is quite astringent.” And: “The seed can be used raw or cooked and can be eaten with the fruit though the seed case is rather fibrous.” And: “Berries will begin ripening from late summer and continue to bear fruit until late autumn.” Also called Japanese silverberry.
Lingaro berry (Elaeganus philippensis): Thorns. Zone 9b. Climbing. Brave AI says they have “a sweet and slightly tart flavor profile. The berries are described as having a currant or cherry-like taste, with the darkest red berries being the sweetest. The flavor is often accompanied by a pleasant aftertaste.” It’s a drought tolerant evergreen shrub.
Goat nipple (Elaeagnus glabra): Zone 7. Thornless! The berries are edible; I’m not sure what the taste is, so it could be anything from very good to very bad. It’s likely to be somewhere in between. The natural thornlessness would be interesting and makes it worth giving a try, though.
SO!
I’m pretty sure I don’t need to chase any other members of the genus! I would still be mildly interested in Elaeagnus macrophylla and Elaeagnus glabra, because they’re thornless and may provide some interesting genes to keep crossing into an Ebbing’s silverberry population, but I definitely don’t need to settle for anything thorny.
It’s amazing that there’s a domesticated hybrid already available that has everything I want.
Clearly I need them!
I haven’t been able to taste the goumi berries. Either they haven’t fruited yet (planted two years ago july 2023) or the birds and squirrels and bunnies ate them all. 
They are thorny but the thorns are long and sparse kind of like mini branches.
Overharvesting is never a concern with invasive species, so they’re the perfect choice of weeds to be eating!