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TREES, PLEASE! Do Valentines Have Vesicles?

By Robin Y. Rivet, for Let’s Talk Plants! February 2023.

New lime varieties bred from native Australian limes. CSIRO Science Image 3592 - CC BY 3.0 <>, via Wikimedia Commons.

Do Valentines Have Vesicles?

Valentine Citrus – peeled and ready to eat - photo R. Rivet.

Single Grapefruit Vesicle - Mvolz, CC0, via Wikimedia Commons.

Yes, red-fruiting Valentines have vesicles - which are the membranous sacs containing the fluid juice, common to almost all citrus. Here in La Mesa, my most beloved backyard citrus is our Valentine tree. It produces about 100+ fruits each season, and we halve and share a pummelo-sized orb every morning during winter months; expecting to share any lingering spheres with friends and guests. With a low-acid and meaty texture, its sweetness hails from Dancy mandarin heritage; the 6.5”+ size and flavor remind one of its ‘Siamese Sweet’ pummelo parent; and the large, grapefruit-like vesicles are raspberry-red, due to anthocyanin from its cross-hybridization with Ruby blood-orange. A royal breakfast indeed!

There’s another blood-red citrus of note (off the radar of most backyard growers) called Smith Red. It’s presumed to be a mutation from a home-grown Valencia, although the history is murky, as the original owner thought her neighbor might be poisoning her tree. I have not sampled this variety, but I will soon, because I have a nursery tree on order, anticipating healthful and delicious juice.

Pink Finger Lime cut in half, with juice vesicles extracted. Ivar the Boneful, CC BY-SA 4.0, via Wikimedia Commons.

Another largely unknown blood orange is the Bream Tarocco. Of the blood-red varieties, Moro is more commonly available, but my taste buds consider the Tarocco flavor superior, and the Bream mutation sports redder vesicles and rind. There are also some new red-skinned Australian blood limes on the horizon, and shockingly, as many as 28 varieties of finger limes are sold in Australia, and not-surprisingly called “caviar citrus”.

However, not all citrus fruits are revered for their fresh-eating vesicles. And, as odd as it might seem to traditional American tastes, many cultures prefer sweet lemons, sour oranges, or bitter limes for their aromatic oils, fragrant rinds or foliage; often more than their flesh. Do the names Makrut, Yuzu, Temoni, or Bergamot ring any bells?

Makrut Thai Lime Fruit Kaffir lime fruit | פרי קפיר ליים

Makrut is another name for Citrus hystrix or Thai Kieffer lime, and the leaves are a mainstay in many Southeast Asian recipes, and the cultivar is readily available in California. Thai lime is sometimes confused with Bergamot, which is actually a sour orange, and its pungent oils have been used in perfumes and Earl Grey tea for centuries. Those flowers are exquisitely scented, the heady fragrance welcomed in sub-tropical garden spaces. There’s also cutting edge research suggesting multiple medicinal benefits for uses of its bergamot’s plant parts, although clinical studies are ongoing.

(Editor's note: See below for more about this topic, excerpted from a back-and-forth email conversation between the author and editor regarding this interesting subject.)

Do yuzus have vesicles? Yuzu is an ancient citrus variety, and its vesicles are likely to be pithy or dry, with bumpy rinds and bitter pulp. In China, yuzu is often cooked to make ponzu sauce, vinegars and teas, and in colder regions of the world, the plant has potential for crossbreeding, as it’s one of the most cold-hardy of all citrus.

But, what’s a Temoni? It has a very thick-rind, and is a bland/sweet citron variety from Yemen, and like Buddha’s Hand, there’s basically no vesicles. The latter is often propagated as an ornamental, since its aromatic rind smells of violets, and around the world there’s many uses for citron including candied, marmalades, scented soaps, spirits and savory dishes.

The word citrus is Latin for citron, and the Swedish taxonomist Linnaeus was acquainted with citron fruit when he named the entire orange family “citrus”. Based on the unique juice vesicles characteristic of most citrus endocarps, the genus might have ended up named “Vesicleus” instead of “Citrus”.



Robin, seated, and Karen finally met IRL (in real life) after the you-know-what at SDBG, 2021. Karen's mother-in-law would say, "kindred spirits always find each other," and she was not wrong.

Excerpt from an email conversation between the author and editor ...

Robin, Hi! Question: I thought Makrut was Kaffir not Kieffer as stated in your article. Please advise… Karen

Hmmm - Karen:

Makrut and Kaffir and Kieffer - I believe all pertain to the same plant Citrus hystrix; with the exception of how the plant may be used regionally in cuisine that differentiate its “common” name. There has been some effort made to move away from calling it “Kaffir lime”, because of the probable nasty origins of the word, even though my research suggested that “kaffir”, was not originally an etymological slur (as is currently used in South Africa), but rather a term for an infidel in Arabic. BTW, there is also a Kaffir Plum, and Kaffir lily – all unrelated; but all I believe from South African slang...

... For my essay, admittedly I was looking to encourage the reader to think about unusual plant names and features. I had never heard of Makrut before, but after learning about it, now I have actually seen it sold… I was quite familiar with “kaffir lime” leaves used as seasoning, but not using the fruit for anything. I had zero idea what the fruit even looked like... the entire article is to stimulate our members to look at their assumptions regarding citrus, and to consider that there may be odd foreign names, unusual cultivars, weird uses, or different customs than our basic and typical grapefruit, tangerine, orange, lemon and limes that inhabit most American kitchens.

Most surprising to me, was discovering that website in Australia with all those finger limes! I’ve been trying to buy a pink one, but had no idea there were so many varieties. The fact that UCR probably has many of these cultivars in their germplasm repository makes me hope we may soon have them publicly available. I have been craving a “Pink Pearl” - or similar for a while..

The bottom line, is that common names of plants gets us all into trouble, even me – who is usually a stickler for avoiding them…Robin

Robin, what a great answer! Thank you. The article sure made me think! BTW- I was proud of myself while first reading your submission as I realized that I am growing Bergamot, Finger lime, Yuzu, Kaffir… Karen


Member Robin Rivet is an ISA Certified Arborist & UCCE Master Gardener – contact her:


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