Remember the last time you indulged in a few daiquiris? If you’re anything like me, your memory might be a little hazy due to having one too many (okay six too many), but try to picture the lime you used.
Did it have seeds? The answer is no, right? It’s not something you notice at first, but upon reflection, it seems weird… Do limes have seeds, or are they, for lack of a better word, barren?
If limes don’t develop seeds, how then do lime trees reproduce? After all, the primary purpose of fruit in nature is to disperse the seeds of the tree on which they grow.
Well, puzzle no more, friend. I’m going to bust this mystery wide open with some insightful citric trivia.
Persian Limes: The Little Green Fruit We Know & Love
Most of us will go our entire lives only ever having tasted one type of lime, the Persian variety, yet there are many different types of lime out there in the big, wide world.
Persian limes don’t develop any seeds, which is usually the result of human meddling, but, surprisingly, the Persian lime is a natural hybridization of citrons and true limes.
Now, some of you might be remembering that time you ate a Bearss lime or perhaps even a Tahiti lime, and think my one-lime life is nothing but a fluke, but – little known fact – these are just different names for the lime of the hour, the Persian lime.
These limes – and any other seedless fruit for that matter – are known as parthenocarpic fruit, meaning they do not need seeds to reproduce.
It’s a little puzzling how these fruits ended up with seedless DNA considering true limes and most varieties of citron do produce seeds, but then again, this isn’t the only way in which this hybrid mixes things up.
Both citrons and true limes are much smaller than their genetic offspring, and true limes (sometimes referred to as Mexican or West Indian limes) have thinner skin, and thus, a shorter shelf life.
How Do Persian Lime Trees Propagate?
With no seeds in sight, you’d think Persian lime trees would sputter out into extinction in the blink of an eye, so how did they wind up becoming the most prevalent variant across the USA?
Well, interestingly, parthenocarpic plants don’t produce seeding fruit because the plants themselves already have all the rudiments required for propagation.
This secret asexual potential could be found in the leaves, roots, or stem of a plant.
For instance, the roots, once spread far enough away from the parent plant, may be equipped to grow a child plant that will eventually crest the earth and thrive as a connected, yet seemingly discrete entity.
Likewise, a leaf might fall into earth from the parent plant and get to work sprouting an entirely new plant — That’s one powerful little leaf!
Parthenocarpic plants can also be propagated artificially by humans via cutting, grafting, layering, or generating tissue cultures, but more on this in just a minute.
Rise Of The Persian: Why No Seeds?
As you now know, Persian lime trees reproduce asexually, meaning they needn’t be pollinated and they don’t produce seeds.
In other words, fertilization is irrelevant to a Persian lime tree, but what in their genetic code has led to this remarkable outcome?
Well, the most common reasons for the emergence of seedless plants are as follows:
- Problems pertaining to pollination
- Problems pertaining to reproductive facilities
- Chromosomal imbalance
It’s the latter of these three influencing factors that gifted us the fantastic Persian lime.
See, typically, the biological architecture of limes is composed of two sets of chromosomes, but the Persian is special! These limes grow from a biological foundation of three sets of chromosomes.
This single set of chromosomes is what separates the seedless Persian lime from its parent fruit, but although many parthenocarpic plants thrive in certain conditions, the Persian lime tree is sadly not one of them.
Persian lime trees can reproduce naturally, but it’s a very rare occurrence, far too rare for this humble asexual tree to meet the demand for limes in of our society.
In light of this, artificial intervention plays a critical role in the proliferation of the Persian lime tree.
Artificial Vegetative Propagation & The Persian Lime
The primary method for the artificial propagation of Persian lime trees is known as “grafting”. Know what a skin graft is? It’s a similar sort of process.
During skin graft surgery, skin is taken from one area, and transplanted onto another. Grafting follows the same principles.
A section of the seedless tree is removed, and then implanted onto a new tree, the eventual result being a clone of the donor tree, which itself, still lives.
It’s a pretty amazing system, one that makes the cultivation of seedless fruits scalable to match hefty societal demand.
Why Go To All That Effort?
Having to graft enough trees to provide all our grocery stores and supermarkets with enough Persian limes seems like a massive undertaking.
Wouldn’t it be easier to choose a seeded lime as our national favorite and let them take care of reproduction themselves?
Yep, it would indeed be easier on commercial fruit farmers, but here’s the thing… Most people want a seedless variety! The lack of seeds makes Persian limes the ultimate in citric convenience, and we’re not willing to let that go without a fight.
Furthermore, as mentioned earlier, the thicker skin of the Persian variety gives it a more robust defense against disease, and thus, a longer shelf life, which is an exceedingly valuable feat in the commercial fruit industry.
Fruit that lasts longer sells more… It’s as simple as that. It also affords more time for harvesting, transportation, and of course, consumption, so, in the long run, the extra elbow grease required for grafting on such a massive scale doesn’t seem such a burden after all.
Are Limes The Only Seedless Member Of The Citrus Family?
While most lemons we buy today are full of little pips, there are numerous examples of parthenocarpic lemon trees, and much like limes, the majority of oranges in grocery stores and supermarkets are completely seedless.
Why we as a society decided it was cool to have seedless limes and oranges but not seedless lemons is anyone’s guess, but my assumption is that it has something to do with the oil that can be extracted from lemon seeds.
This stuff is used in a number of lotions and shower gels, as it has a fresh, “clean” scent, and it’s an effective moisturizer.
I’m no dermatologist, but I can only assume that, comparatively speaking, lime seeds just aren’t as useful for anything other than growing more lime trees.
Do Other Popular Limes Have Seeds?
Okay, so we’ve established that most limes on sale in the US belong to the Persian variety and are seedless, but what about other notable types of lime? Let’s find out!
Are Kaffir Limes Seedless?
Kaffir limes (Citrus hystrix) are enjoyed across the entire continent of Asia and can usually be identified by the bumpy texture of their green skin.
Particularly acidic limes, their juice hits the tongue with a piercing tartness, but there is less of it than can be found in Persian limes, and, what’s more, they do develop seeds.
Are Philippine Limes Seedless?
Philippine limes, or if you want to be scientific about it, Citrus macrocarpa, are another example of a hybrid specimen, and as far as limes go, they’re quite peculiar.
They have orange rather than greenish-white flesh, and they’re positively bursting with juice.
As you can glean from the name, they’re most prevalent in the Philippines, but they’re also quite popular in many other South Asian nations, where they may be better known as calamondin.
Used as both an ingredient and garnish in Southern Asian cuisine, it wouldn’t be long before you ran into one if you traveled to the bottom half of the continent, and when you did, you’d find they do indeed have seeds, 8–12 to be exact!
Are Finger Limes Seedless?
If you thought Philippine limes sounded kind of funny, get a load of these wacky fruits!
Finger limes look more like baby cucumbers than limes, hence their name, but you might also hear them referred to as Australian finger limes or, due to their pearl-like flesh, caviar limes.
They have long cylindrical bodies with an apex at one end and incredibly rough, bumpy skin. Their juice is particularly sour but heartily refreshing.
Multiple different color finger limes can be cultivated, but every single variant is seedless.
Are Blood Limes Seedless?
For a lime with such an ominous name, these fruits are wonderfully sweet and tasty — The blood part comes from their red color inherited from their parent plant, the red finger lime.
The other half of their genetic makeup is derived from the Ellendale mandarin, another Frankensteinian hybrid comprising orange and mandarin.
Blood limes tend to be a little smaller than most others (especially Persians) and always produce seeds, but the most interesting thing about them is that, much like kumquats, they’re eaten as one… skin and all!
Are Rangpur Limes Seedless?
If you cross breed the mandarin with the citron, you’ll end up with Rangpur limes (Citrus jambhiri Lush).
Often classed as Indian mandarin limes, Rangpur limes look more like miniature oranges but aren’t too far detached from the limes we’re all familiar with in terms of taste.
Rangpur limes are most often used to make marmalade, and they do have seeds.
Are Lime Seeds Edible?
Limes are a remarkably healthy fruit, brimming with vitamin C and antioxidants, but what about the seeds?
As small fruits, any non-parthenocarpic lime will have minuscule seeds, so it’s very possible that you’d ingest one by accident, but the good news is that it won’t do you any harm — Hooray!
Seeds found in fruits such as apples, cherries, and nectarines contain toxins, and if swallowed in large quantities, can make humans and animals very ill, but limes don’t belong to this sinister family of fruits.
Having said that, if you suffer from bowel conditions such as IBS or diverticulitis, excessive consumption of lime seeds may cause gastric distress.
So, do limes have seeds? Yes and no — The common Persian lime that lines the shelves of our grocery stores and supermarkets does not, but many other types, such as blood, Rangpur, Philippine, and Kaffir limes do!
Limes that do not produce seeds can self-propagate, but in the case of the Persian lime, it’s a rarity.
In light of this, farmers intervene in order to trigger artificial vegetative propagation and make this famous lime commercially viable.