Why Your Grocery Store Limes Never Have Seeds

Let's get this out of the way: Some limes do have seeds, more on that later. However, most common grocery store limes do not have seeds. These common limes are called Persian limes. Biologically, plants producing fruits without seeds is called parthenocarpy. Parthenocarpy is the ability to produce fruit without pollination. This almost never happens naturally, that is, without human intervention or design. For Persian limes, this is because they are a cross between a key lime and a lemon, which are themselves hybrids of different citrus fruits. All this hybridization causes Persian limes to have three sets of chromosomes, which really messes up seed production apparently. This is basically why your grocery store limes do not have seeds. 

You might then wonder, like me, how these limes are produced year after year. In order to propagate and grow seedless limes, you actually have to graft a branch from a seedless lime tree to a new tree, creating a clone. 

Key limes are indeed different from Persian limes, but not just because they have seeds — they also have thinner skins making them hard to transport. Other famous seeded limes include the sweet lime and the rangpur lime, of Tanquerey gin fame. Sweet limes lack acidic bite, and rangpur limes look like oranges but taste like limes. Not only are these harder to find, they're also inconvenient to use because of their seed content.

We're always looking for convenience, like bottled lime juice (which is totally fine to use by the way). This might help explain the immense popularity of seedless limes. We don't actually know where Persian limes come from, as they've been around for a long time. We have no idea how this specific hybrid of citrus came about. It's theorized that Persian limes were introduced to the Mediterranean by Iranian traders, but there's no definitive proof of exactly when. We do know that these seedless citrus fruits eventually made their way to Brazil, and eventually California.  

Seedless limes offer numerous benefits. They have more juice per lime, and a result of this specific hybrid means these limes aren't as bitter as key limes. They also have plenty of vitamin C (though key limes edge them out just a little), and most importantly of all, you're not digging seeds out of your lime juice!