Here is a photo of the biggest seedling. Hope it helps. Looks like it just got its first set of leaves.

Ok. Should have looked first. Maybe a Merdeka, hystrix (kaffir lime) and the citrus macrocarpa (calamansi) hybrid.

This post was edited by Gyr_Falcon on Fri, Oct 31, 14 at 0:42

That's what I was thinking initially too. But these fruits are HUGE! Do kaffir limes even get this big? From pictures I've seen, they seem to be in the size range of a lime/lemon. Also, their leaves seem to have a distinct "double lobe" to them, like in the picture I found online (below). The seedling I grew from the fruit doesn't have that kind of a leaf.

Sorry, I was editing while you where posting. :)

Ugli fruit?

You should take a pic of the entire plant and a closeup of the leaves. Do the leaves have winged petioles? Are there thorns on the branches? How long?

Also, cut the fruit in half (like at the 'equator') and post a pic. Arrangement of the segments, thickness of the peel and number of seeds are helpful in identifying.

Citrus forum people would also be a good place to run this by.

That fruit looks like a citron (Citrus medica), one of the 3 original species from which all of today's citrus fruit are derived. I know OP says he is familiar with them, but there is a huge diversity of fruit form within the species, even on the same tree.

I've seen them commonly in India, where they're known as Madhankri, and are usually made into a sour but tasty pickle.

Here is a link that might be useful: Citrus medica

This post was edited by shaxhome on Fri, Oct 31, 14 at 11:55

Hi everyone,

Thank you for your help in trying to ID this citrus. The mystery of this plant continues.

I had a chance to go back and see the parent plant this morning and took some pictures to help with the identification. I admit I'm very inexperienced in citrus identification, but to my limited knowledge, the citrons don't have a winged petiole on their leaves as this plant does. So I doubt its a citron, although some of those varieties did look rather similar to this in terms of the fruit itself. It also does have thorns as you can see in the pictures below.

I took 5 pictures, but I don't know of a way to post more than once picture per post. So I will do 4 more posts below, one for each picture. I apologize if this violates forum etiquette. In included foliage, fruit, open and closed blossoms.

Thanks again for your help!

Photo 1 of 5:

Photo 2 of 5:

Photo 3 of 5:

Photo 4 of 5:

This particular fruit was a little bit smaller than the original one I took before and posted in my original post. This fruit probably measured about 5 inches or so in length and was probably the most "ripe" of the 15-20 fruits on the plant right now.

Photo 5 of 5:

Closed blossoms on the plant.

These are great photos and hopefully very helpful for someone knowledgeable in citrus IDing.

I would strongly suggest you link to this thread over on the Citrus forum. There are growers all over the world who might be able help you with this.

You might also cut a fruit so someone can see the inside -- number of seeds, thickness of rind, etc.

I'm not convinced it's a lime, actually. I am thinking it looks more like a lemon that simply hasn't ripened. We once ordered a Meyer lemon tree on line and the fruit was green for months.... all summer. I called the company, convinced they had sent us a lime tree in error. They didn't call me an idiot (at least not to my face) but they did explain that it takes them months to ripen and to expect that particular lemon to ripen in October. It did, and it has been blooming and producing fruit year round.

Although the nubby fruits you showed are not typical of most lemons, the texture could be the variety - either a "rough"lemon, or the Ponderosa lemon. If it's a lemon, it would be segmented inside just like other typical citrus if you cut it cross-wise. I would keep watch on it. My guess is over the next moth or so, the fruit will ripen to a nice bright lemon.

The flowers and thorns especially remind me of a lemon... we have had a couple of different lemon trees, including the aforementioned Meyer lemon, and the fruit can get quite large. Our Meyer is quite late to ripen this year, although we have one fruit starting to get some color just this week. The rest still look like little limes..

Some lemons bloom and produce fruit year round. Others produce ripe fruit by early summer and then rest. The blooms and buds you showed look exactly like ours and are generally quite fragrant and those thorns are typical. Watch out... they can be nasty!

Below is a photo of our newest Meyer lemon. We recently moved to California and had to leave all of our potted plants and our wonderful garden behind. You can see the one fruit on the left starting to ripen while the rest still look like limes.

Did anybody mention Ponderosa lemon yet?

Yes, kathyannd mentioned Ponderosa lemon in the post before yours. ;-)

Oops! Thought I read them allâ¦.

found these bad boys in the back of a friend's house while landscaping.

Hmm... my photo's won't upload. I'll try later.

start your own post tyler ... unless it adds to the prior ID .... ken

It may be a Rough Lemon. I just posted about these over on the Florida Gardening forum. They are a cross between a mandarin and a citron. It should get yellow as it ripens.

I have the same fruit and tree! I had over 30 of them this year. And there as much pulp as fruit. They are kaffir lime. I purchased the tree from the grower when it was just 2 feet tall but was labeled kaffir and the leaves are kaffir, but the fruit is huge! I made jam from it this year which is very good. They are the size of soccer balls!

Ponderosa lemons look like that. They are a citron ×pomelo crossing???

No, I don't think they are ponderosa lemons. I have the exact same tree and ponderosa lemons are rounder. We are also trying to find out what type of citrus they are.

I have the same thing and they are rock hard! It's growing under my lemon tree so i thought it was a self seeded but it's just like yours!

brian, it could be Citrus macrophylla or Citrus × jambhiri -- both are used as rootstock for lemons.

That would make sense considering where i found it... Is the fruit edible? Maybe i just graft a piece of my lemon tree onto it?

Citron showing rind/pith.