'Succulent Plant Encyclopedia PUKUBOOK' is a site run as a personal hobby—basically, I just collect and introduce my favorite succulents however I like. Still, I do feel a bit of a mission here, and one of those is “Let’s try to clarify and properly distinguish plant varieties that are circulating out there with vague or confusing labels.” I get especially fired up when it comes to those less mainstream varieties that everyone seems to gloss over—in other words, the ones that are just being swept along. I know it’s kind of pointless, but I can’t help myself.

So for this edition, we’re shining a light on exactly those “overlooked and vaguely identified” plants. It’s a deep-dive special that really nobody asked for.

Japanese Sites

First off, let’s try googling “Crassula 紫蝶” in Japanese.

Some websites and shops list it along with its scientific name, and most basically call it “Crassula clavata.” The photos look like this.

Next, let’s search for “Crassula clavata.” Here’s what comes up.

Wait—don’t they look different? True to the “clavata” name, the leaves are club-shaped and chunky, which gives a very different vibe from the flat-leafed “Purple Butterfly.” It feels like more than just a difference caused by growing conditions (Crassula, after all, don’t tend to change shape that much by season). Maybe they are distinguished with the ‘Purple Butterfly’ name because they’re not the same? You could argue that—but who knows.

Overseas Sites

Now, let’s check foreign sites under “Crassula Purple Butterfly.”

Both the plump “clavata”-looking types and the thin-leaved “Purple Butterfly”-looking types appear together. Of the ones clearly labeled “Purple Butterfly,” most have thin leaves. The scientific name listed is usually clavata, and both the use of parentheses and naming situation are just like in Japan. Does this mean the identification is correct after all?

Catalogs from Overseas Growers

However, when I looked at a Chinese grower’s catalog I often use, ‘紫蝶 Crassula platyphylla’ was written there. That’s actually what got me curious. At first, I wondered, “So is Purple Butterfly actually platyphylla?” But then, almost every source I checked calls it clavata. So does that mean the grower made a mistake?

Just to be sure, I tried searching for “Crassula platyphylla”…

Isn’t this more like ‘Purple Butterfly’?

GBIF

Here’s where the most reliable source comes in: the plant taxonomic database GBIF. When I started PUKUBOOK, most plant databases—including this one—were basically just lists of names with almost no other info. But these days, GBIF is amazing: it provides not only distribution and habitat info, but also actual habitat photos taken in the wild and herbarium (specimen) images attached to research papers. Even non-experts can get a pretty good idea what a plant is like. GBIF is awesome.

Here’s clavata.

And here’s platyphylla.

Both are originally varieties of “nudicaulis,” so they’re pretty similar, and there are even photos showing similar forms. Still, clavata tends to have thick, fleshy leaves, while platyphylla’s leaves are flatter.

Once again, ‘Purple Butterfly’ really does look more like platyphylla.

Conclusion

I have no idea! (lol)

But that’s only natural. I’m not a botanist, and I haven’t done genetic analysis, so I can’t definitively identify whether a given specimen matches a particular wild species. As you can see from the GBIF photos, even within a single species you’ll find a range of forms—maybe it’s seasonal, or just individual variation. There’s also a good chance that ‘Purple Butterfly’ is simply a selected flat-leaf form of clavata.

However, since I haven’t found any conclusive evidence that “Purple Butterfly = Clavata,” I’ll refrain from listing it as “clavata Purple Butterfly.” PUKUBOOK isn’t about deciding what’s the one true answer—it’s about listing all the possible identities side by side, as long as they’re plausible. And since there’s even a catalog out there listing “Purple Butterfly = Platyphylla” as a possibility, I’ll just keep it on a page as “Crassula Purple Butterfly,” and link to both clavata and platyphylla.

Side Note

This kind of nitpicky research is exactly what I’m always fiddling with in my downtime, and it’s that collection of random bits of info that makes up PUKUBOOK. There’s pretty much zero demand for this sort of info now, but I can’t help hoping that it’ll be useful to someone, someday.