Brahea edulis grows wild in exactly one place: Guadalupe Island, a speck of volcanic rock off the coast of Baja California. Fan-shaped leaves, a thick grey trunk, and a tolerance for drought and salt spray that few other palms can match. Landscapers plant it because it survives neglect. None of that makes it a date palm.
A different genus, not a different variety
The species we deal in, Phoenix dactylifera, sits in a different genus entirely. Guadalupe palm and date palm share a family (Arecaceae) the way an apple tree and a pear tree share one — related, but not interchangeable, and definitely not two names for the same fruit.
"Edulis" is doing some work in that name
The Latin means edible, and it's earned. Guadalupe palm produces small black fruit that birds and the occasional forager eat straight off the tree. But edible and commercially grown for eating are not the same claim. Nobody plants a Guadalupe palm orchard for its fruit the way growers plant date gardens in Madinah or the Jordan Valley. The fruit is thin-fleshed, mostly seed, and was never bred for size or sugar the way Phoenix dactylifera has been bred for well over a thousand years.
What actually separates the two
Climate is the first split. Guadalupe palm tolerates coastal fog and thin soil. Date palms want the opposite: long, dry, punishing summers and irrigated roots, which is why the world's date belt runs through the Gulf, North Africa and the low deserts of California and Arizona rather than anywhere near an island fog bank.
Breeding is the second. There's a long list of named date cultivars precisely because growers have been selecting for fruit quality for centuries — you can read the cultivar list Phoenix dactylifera actually has and see how deliberate that selection has been. No comparable cultivar list exists for Brahea edulis, because nobody was ever selecting it for fruit.
Use is the third, and the simplest. One ends up in a botanical garden or a drought-tolerant front yard. The other ends up in a box on a kitchen counter, and getting from tree to box involves an entire growing discipline — we've written before about how commercial date palms are actually grown, and it looks nothing like landscaping an ornamental fan palm.
Why this matters if you're buying
It mostly doesn't, unless a nursery catalogue and a food supplier catalogue get mixed up in the same search. If you're after dates to eat, sell, or gift, the name to look for is the cultivar, not the genus name of every palm that happens to be edible in the loosest sense. Start with picking a wholesaler that deals in the real thing rather than a nursery that happens to stock something with "edulis" in the name.