Let’s talk about some of the basics of what you need to know to grow Lithops, and the foundational knowledge that you’ll need to rely on to find exactly what you’re looking for.
As with many highly desirable plants, these little mesembs are victim to two of the biggest problems that can be faced in plant cultivation: poaching, and scams.
There is no ethical collection of Lithops plants from wild populations, even if in decades past, that’s how they were collected and identified. In modern times, the populations are too threatened by human development and poaching from unscrupulous people to justify any collection of wild material. Foundational material for identifying Lithops came from field collecting in the early to mid 1900s, but just like we now have color TV, voting rights for women, and electric cars – times have changed.
As far as scams go, if you are like me and trying to collect specific plants with specific appearances, knowing how to identify what you like and understanding how the naming and classification works is a huge help. If you’re going to pay a premium for a specific seed-grown plant with a known Cole number, it helps to know what you’re looking for so you aren’t taken advantage of.
With that: let’s begin!
Lithops Background
Because Lithops are known from specific colonies and locations in South Africa, there’s specific terminology to describe their appearance. In addition, those who grow these in cultivation often select for certain appearances, and over time they may be able to produce them consistently enough to name it something separate.
I’ll be basing my descriptions here on a few books in my library:
- Lithops: Treasures of the Veld by Steven A. Hammer – not currently in print, but you may be able to find a copy
- How to Grow Lithops and Other Living Stone Plants by Piotr Dzieduszynski – a newer publication, very nicely done, although it is in both Polish and English. Piotr has one of the largest collections of Mesembs in Poland, so his insights into cultivation come from more northern and colder conditions.
- Lithops in Habitat and Cultivation by Roy A. Earlé and Janice E. Round – A book I was only able to order directly from the publisher when it was offered in the Mesemb study group I’m a part of. Gorgeous illustrations and incredibly detailed in terms of specific locales and descriptions.
What are Cole Numbers and Why Do They Matter?
You’ll see on many of my Lithops seedlings and even some older plants some combinations of numbers and letters, most often starting with a C like the plant at left (C36A).
The C-number is a “Cole Number”, referring to a number assigned by the husband and wife pair of Desmond T. and Naureen A. Cole. According to Hammer’s book, Naureen sent quite a few intact seed capsules northward to Europe, which made much of the plant material and species she documented highly accurate and true to wild-type plants.
When your Lithops seeds have Cole numbers, that’s an indication that they come from ‘pure’ seeds pollinated (often by hand) to ensure only plants of the same Cole number pollinate each other. It gives a precise indication of what the plants should look like, and you can even trace (roughly) the exact spot your original Lithops great-great-grandparents may have come from.
As Hammer goes on to note in his book, though, the Cole seeds represented very specific clones and very specific genetic material that originated from wild plants. As time goes on, however, those of us growing them in cultivation tend to select for traits and appearances we like best. He comments on whether we’re being a bit facetious to continue to hyper-focus on specific locales and their appearance when cultivating them, as even the source material may have been limited to certain clones compared to the wild variability of the species.
All this to say:
The Cole Number indicates that the original seeds of the plant you’re growing can be traced back to a specific, labeled source material of Lithops seeds originally collected by the Coles. It should indicate a specific appearance, and there should be a certain degree of provenance (knowing the earliest history of the seed’s family tree). You cannot identify and apply a Cole Number to a plant simply based on looks. Because Cole Numbers imply that the plants trace their genetic material to the original seeds, if you don’t have that proof, your plants should not have a Cole Number assigned.
Most Lithops you see for sale won’t have a Cole Number
And that’s okay!
Cole numbers only matter if you’re trying to get a very specific plant that looks the way they do in the wild. Your average big box store lithops is often grown from open pollination in large quantities, which is how they’re able to keep costs down. Hand pollinating locale-specific clones is a lot of labor!
There’s no shame and absolutely no harm in buying a Lithops just because you like the look of it. My in-ground planting (blog post about that coming soon!) is entirely of nursery store plants that I simply liked the look of. But…because these can be so similar, don’t assign a Cole number or species name if you’re not certain.
A seedling from the same batch as the earlier photo, showing minor variations typical even in seed from a specific cultivar.
Understanding Latin Names
I’m admittedly not the strictest adherent to spelling out the full latin name for every single plant in my collection, but to be fair, I have anywhere from 500 to 1000 seedlings growing at any given time.
A quick refresher on basic taxonomy for those of us who’ve forgotten about “Kings Play Chess On Fuzzy Green Stools”.
K – Kingdom
Is it plant, animal, single-celled organism? That’s sorted up here.
P – Phylum
Mostly used to indicate ancestry, and how distantly related something is.
C – Class
Used to indicate a comparable level of complexity – in plants, this is way weirder than animals, but we can ignore it for this post.
O – Order
Again, in plants, we went weird. It’s mostly used to sort things into manageable groups.
F – Family
Essentially large groupings of similar plants in terms of evolution; for Lithops, they’re in the Aizoaceae family. Interestingly, Aizoaceae didn’t catch on as a catch-all name for similar plants – anything you’ve heard referred to as a “mesemb” is in this family, but not necessarily in the Mesembryanthemum genus.
G – Genus
Smaller group within the family with more similar characteristics, but not identical – in animals, wolves, coyotes, and dogs are all in the same genus, but it’s easy to tell they’re not the same species. While we’ll call Lithops a “mesemb” (short for mesembryanthemum), they are not in the same genus. For all Lithops, their genus is…Lithops!
S – Species
Precise: This is where you get a specific appearance, growth habit, or flower color. Species within a genus can often inter-breed, but different genera (plural of genus) usually cannot.
This matters when it comes to Lithops because it helps you figure out exactly what plant you have, and understand where it comes from. Lithops are unique in that we have some of the most detailed collection data and history of plants in a given genus, so we’ve been able to be far more precise than the average human often cares about.
When trying to figure out what a given Lithops is, there’s a further nomenclature breakdown.
Subspecies (denoted with ssp.) – somewhat physically and genetically different from the rest of the species, but still close enough to breed with the main speices.
Variety – (denoted with var. or v.) – genetically inherited characteristics that differ distinctly enough from the main species to be notable. This is below subspecies, meaning a given subspecies can have one or two or more varieties within it. Does not mean it’s been man-made or created from selective breeding (although it can be used to denote that).
Cultivar – (denoted with cv. or c.) – the plants have been selectively bred to exhibit desired traits.
When it comes to Lithops, you can get as specific as a cultivar from a variety of subspecies within a species. You’ll see this the most often in some of the more variable species, such as L. karasmontana or L. gracilidelineata. A few examples of how you might see this written out (pulled from my latest seed order):
- Lithops gracilidelineata ssp. gracilidelineata var. gracilidelineata
- Lithops dinteri ssp. dinteri var. dinteri cv “Dintergreen”
- Lithops bromfeldii var. glaudinae cv “Embers”
- Lithops pseudotruncatella ssp. elisabethiae cv “White Queen”
All of this subspecies, variety, cultivar detailing is a way for folks to very clearly indicate what the plants will look like, including noting whether it was a man-made selection from a given wild population (as in the dinteri or bromfeldii examples) or if it’s a wild variation that’s been maintained in cultivation (such as the gracilidelineata plant).
Confused? Don’t sweat it.
If you like the look of a plant, get it. It’s that simple. The name matters when you want to make claims or produce seed, but for a single specimen you want to grow just because you like it?
Call it the super duper fairy dust specimen if you want. It’s your Lithops.
It’s not just Cole Numbers and Cultivars
If you squint at the photo above, you’ll see that the esteemable Steve Hammer (whose plants are pictured) has labeled that pot with “ex 94” (or maybe 97).
In Hammer’s book, he notes that Ernst Fritz was another important source, who often selected and collected very large specimens (or simply grew them big in his greenhouse). Ernst Fritz passed in 1986, to give you an idea of how long ago collecting wild specimens may have been accepted, but his material was also scrupulously well documented. Most Lithops follow a Cole number designation, but if you see something different, it’s worth asking if it came from a different 1900s collector.
My own seed comes from a handful of sources, and I tend to keep notes on where my seed comes from (my UK study group, a South African nursery, a lovely Czech grower whose collection was sadly decimated in the recent bombings, Mesa Garden, etc). A convention I don’t often see but is worth noting, as seen above in Hammer’s label, is using “Ex: [origination]”. EX in front of a Cole Number or similar indicates that it comes from that previous grower – i.e. seed from “Lithops julii ex-C205″ indicates that the seed came from controlled conditions ostensibly from Cole collection plants.
As noted in the forum I linked, it’s incredibly rare to encounter anyone who maintains the same level of controlled conditions, notes, or even has the same degree of original plants as a collector such as Hammer or other European growers (such as the Polish grower, Piotr). If you do see someone who has plants or seeds labeled with an “EX [name/number]”, though, it’s worth asking about.
Seed lot Numbers and Note Taking
Personally, I always label my seed pots with the seed lot number (if available) or other notes on where the seed came from.
At right is one of my Mesa Garden seed Lithops with label showing:
Genus – Lithops
Species – karasmontana
Subspecies – bella
The subspecies bella has quite a few varieties and cultivars, but this one does not have a Cole number or anything more specific than the subspecies.
When viewing the description, this is simply “highly variable, s Pockenbank”. Keeping a record of the exact seed lot I purchased and grew these seeds from helps those who buy my plants learn as much as they’d like about what they’re getting.
Plus, having the precise labels helps when it comes to my dozens and hundreds of seedlings. The year I sowed these seeds (2022), I had 3 different lots of karasmontana seeds – 2 specific Cole numbers, and this one without one.
Do you have to keep such meticulous records?
No.
If you’re just starting out with a big box store Lithops of dubious and likely hybrid origin, it’s overkill.
But as you start to expand your collection, it becomes a point of pride to be able to point to exactly clones and cultivars of specific types. Once you start producing your own seed, that’s when it reaches a new level and the degree of precise labeling becomes critical.
Does this all sound …a bit much?
That’s fine.
It kind of is.
If what you’re looking for is just a straightforward guide on how to grow your Lithops, I’ll have more posts about that in addition what I’ve written in the past. In the meantime, let us nerds be nerds about our little butt plants. We like it that way!
If you want some of my seed-grown lithops, I invite you to check out my shop! As I have plants established enough that I’d be happy to get them in the mail, I’ve started listing them in the shop. As of this post (May 2024), I don’t have any Lithops seed planned, but there are quite a few cacti producing seed that I offer. Any lithops in my shop are from ethically sourced seed, and I’ll note that source in the description.
