Con Artist (Homalomena 'Emerald Gem')

I'm very much of two minds on this one. All the plant-seller websites tell me that it's a super-easy plant; my actual experience with it has been decidedly mixed; and lots and lots of other people have had a really tough time with it.

If you do a web search for Homalomena¹ 'Emerald Gem,' you will inevitably run into sites that praise the hell out of this plant. You'll read things like, Compact shape! Tolerates low light! Disease resistant! Tolerant of stress conditions! The perfect choice for an area with height restrictions! Humidity is not critical! Easy-care! Remains lush and healthy! Durable foliage!² In fact, the word "durable" and variations on "durable" are repeated in almost every profile.

This raises some questions. Like, what does it mean for a houseplant to be "durable?" Exactly what sorts of conditions can it survive because of its durability? If it's so durable, why are all its leaves turning yellow? Nobody ever says.



For my own plant, this was never really that big of an issue, because I got it cheap ($3) and only got it because . . . well, because it was cheap, and because I wondered if it would work for me.³ So, you know, durable or not, who cares. That was about eight months ago, and although it doesn't look as good now as it does in the above picture (which is from October), it's still alive, and it gets by okay.

The number one problem actual people will report to you about this plant is that it drops its lower leaves. A lot. I'll be blunt: I do not know why this happens. I would normally assume that it's from overwatering, and watering is probably a factor in there somewhere, but my plant doesn't drop leaves with any kind of predictable pattern at all. I have no idea what it wants me to be doing differently.

The two concessions to reality that (some of) the plant sellers make are, they tell you 1) don't leave the plant to stand in water, and 2) don't let it get cold. There's wide disagreement about exactly how cold is too cold, but I've seen warnings about 70ºF (21ºC), so be aware that we may be talking about a plant with a pretty extreme understanding of the word cold. My problem might be temperature: the plant is a reasonable distance away from any doors or windows, but it's probably not so far away that it never dips below 70ºF.

We had an opportunity to get some of these in, on the last tropical plant order we placed. WCW⁴ nixed the idea, on the grounds that Homalomenas⁵ have not been easy to maintain in the greenhouse in the past. This is easily explainable, though, if we accept that they might start throwing leaves at 69ºF: certain areas of the greenhouse are at or below that temperature all the time in the winter.

When customers ask for recommendations for dark spots, I run through the standard list pretty quickly⁶, and more often than not people don't like any of them. So more options are always nice, and Homalomena would fit the bill if I could recommend it with a clean conscience. As it is, though, it's too difficult to recommend to most people, we can't keep it in the greenhouse anyway, and if neither of those were a problem, there's still the issue of it not really looking that exciting. The leaves are nice, true: they're shiny, they're green, they have an interesting texture, and the plant is self-heading, but all of that also applies to Spathiphyllum spp. or Zamioculcas zamiifolia, which are also much easier plants, and the first even has attractive flowers into the bargain.

Which brings me to the other adjective that all the plant-sellers bring up for Homalomena: "compact." This probably is a legitimate selling point for this plant: they aren't likely to outgrow whatever space you put them in.⁷

Look! A ladybug!

As best as I can figure out, here's how you grow one:

Light: flexible. I wouldn't put one in partial sun, but filtered or reflected sun should be okay. And, actually, my plant was doing pretty well during the summer when it was getting about an hour of direct sun every day.
Water: Bless me, I have no idea. Overwatering is bad, underwatering is bad, standing in water is bad. Mine gets watered about three or four days after I can't feel moisture in the soil anymore, and . . . well, and it's still alive. The growers' guide helpfully suggests that they be kept "on the dry side."⁸ They may be one of the plants that people overwater just because they have a tropical look and people assume they must need a lot of water. (Dracaena fragrans and Aglaonema spp. have this problem in spades: it's very hard to convince people that the plants would be happier if they were cared for less. This is also the reason why I think I used to have trouble growing Dieffenbachias: it seemed like anything with such watery stems and such broad leaves had to be thirsty all the time. But no.)
Humidity: Nice if you can get it, but seems not to be critical.
Temperature: Already covered above.
Pests: I assume it's probably subject to the same ones as any other plant. I've yet to have any pest problems with mine, and pest / disease resistance is supposed to be a selling point, but considering how hard the plant sellers are hyping the plant, I'm thinking the pest resistance may be overstated too.
Grooming: One does get tired of picking off yellow leaves, though it's not like you're doing it constantly.
Fertilizer: I've fed mine once or twice, but really don't know what it needs exactly. My growers' guide says they're pretty heavy feeders, though not insatiable, and they're also sensitive about high levels of soluble salts in the soil, so it's potentially a bit of a catch-22.
Propagation: I assume that plants like my own, which have multiple plants potted up together, can be divided fairly safely, but beyond that, I have no idea. The growers' guide says they're mostly from tissue culture.

The hype isn't the plant's fault, obviously, but even so, somebody is being a little dishonest. They're not all that easy to grow, and it's a little cruel of the tropical foliage industry to suggest otherwise. I understand that business is business, and people are in it to make money, and it's hard to make money if nobody buys your plants, but it seems to me like there's not much money in convincing people that they have black thumbs, too: people who think they have black thumbs don't buy very many plants. Either give better instructions, or acknowledge that it's maybe not the easiest plant, you know?

EDITED 5/13/08: It actually got worse, so I raised the difficulty level from 5.5 to 6.7. We seem to be arguing mostly about how much water it deserves, but it's also not bouncing back since I started trying harder. I'm afraid its days are numbered.

EDITED 10/21/09: We seem to have come to an understanding of some kind on the watering; I'm watering less, and it's doing okay, so I've re-evaluated the difficulty level and now consider it a 5.6. (Subject to change, of course.)

EDITED 1/20/10: Not sure what changed, exactly, but it's behaving itself just fine now, so I moved it down to a 3.8, which is approximately "normal" difficulty. The location it's in at the moment has a bright fluorescent light about 2-3 feet above the rim of the pot, it's warm all the time (because it's near the ceiling, in the kitchen / living room), and I water it when it begins to droop a little. The drooping is pretty subtle, unfortunately. I'm also feeding it, and I wasn't before, though I'm not giving it a lot of food. This all seems to be working out just fine, so possibly it was over-potted before and has only now grown into its pot, or it really does begin to throw leaves at 70F/21C and is only happy now because it's never that cold, or it's not the low-light plant it's advertised as being. Something doesn't add up about all this, but it's working now, so I'm not going to complain.

-

Photo credit: both my own.

¹ This is actually pronounced "Hahm-uh-low-MEE-nuh," but I always pronounce it "HAHM-uh-LAW-muh-nuh," for reasons which will be explained shortly.
² (All are actual quotes from various websites, in case there was any doubt.)
³ Also, I enjoy saying "Homalomena," the way I pronounce it, which inevitably gets this stuck in my head:
.
The ultimate expression of this association is that now my husband or I will automatically sing "doo doo de doo doo" in response to the other of us saying "Homalomena," which I hope we never have to explain to anybody we don't know.
⁴ = Wonderful Co-Worker, the other person working in the greenhouse right now, who has been mentioned repeatedly in the blog already.
⁵ (Doo doo de doo doo)
⁶ Dracaena fragrans, Dracaena deremensis cvv., Aspidistra lurida or A. elatior, Spathiphyllum spp., Sansevieria trifasciata, Zamioculcas zamiifolia, Aglaonema spp., Philodendron hederaceum, Epipremnum aureum, and Chamaedorea elegans, more or less. Sometimes also Rhapis excelsa, Chlorophytum comosum, and Chlorophytum x 'Fire Flash,' depending on how low they seem to mean by "low."
⁷ Particularly not if you kill the plant.
⁸ The dry side of what?

Unfinished business re: Ficus benjamina

Among other things, when I did the Ficus benjamina post, I noted that we were supposed to be getting yet another cultivar, 'Exotica,' at the end of last month, but that I didn't know what it was going to look like or whether it would be worth mentioning.

Well, 'Exotica' probably really isn't worth mentioning, but we got it and others in, and I feel like I would be a little remiss if I didn't post pictures of them, too.

Also, I've decided that as a service to PATSP readers (and as a way to get even more plants in a way I can justify to myself), I'm going to try a leaf-to-leaf competition between the various F. benjamina cultivars. I've taken four cuttings of five different plants, and am rooting them in perlite, and the idea is that we'll just see whether any of the hype about them being easier, improved varieties is justified. (There might be a sixth, because I might do cuttings of 'Midnight' too, though I have 'Midnight' already and we all know what it looks like and space is kind of an issue.)

So. First, the full-length photo of 'Exotica:'



This cultivar turns out to be okay: the leaves are longer and narrower than on a standard F. benjamina, and they also feel a little stiffer, but beyond that it's kind of hard to tell. The plants we got arrived looking like crap: they had basically a ball of foliage like you see in the picture, with three or four branches that were another two or three feet beyond that. The branches in question were pretty droopy. (I guess the more positive word for that is "weeping.") Also, the plants we got had the same problem that a lot of our plants from Florida have, which is that they arrive with gray stuff covering the lower leaves. I've speculated before that the gray stuff is probably a combination of pesticide residue, hard-water spotting, and dust. It doesn't clean off well, and is a pain to deal with, and there are enough leaves that I don't really relish the idea of trying to clean them by hand, though that's probably what I'll wind up doing.

Then there's 'Black Diamond:'



This one I've gone back and forth on. When we first opened the boxes of plants and I saw the variegated leaves, I was really excited, because that shore is some fine variegatin', there. But then when I pulled them out of the box and realized that only the new leaves have the variegation: the older leaves turn into 'Midnight,' which is nice, but I already have one. So I calmed down. 'Black Diamond' is still pretty, though, so I eventually compromised by taking some cuttings, which is part of the impetus for this whole Ficuspalooza project.

Ficuspalooza:

(L-R) 'Black Diamond,' 'Spearmint,' 'Monique,' 'Exotica,' 'Starlight'

'Black Diamond'
'Spearmint'
'Monique'
'Exotica'
'Starlight'

For the record, 'Spearmint' and 'Starlight' really are different cultivars, though I'm not sure how easy that is to tell from these photos. (They were all taken at the same time, in the same light, though, so any differences you see are those of the real plants, and not from the photography so much.)

'Starlight' came to us in hanging baskets, for some reason, which strikes me as crazy -- who ever heard of a Ficus benjamina in a hanging basket? Because of that, I didn't take a picture of any of them as whole plants, but you'll just have to trust me: the background color for 'Spearmint' is kind of cream-colored, but 'Starlight' is actually white, and 'Starlight' has more white than 'Spearmint' does cream. Also the green parts are different as well, with 'Spearmint' being more of a gray-green and 'Starlight' being more green-green. 'Starlight' is definitely the prettier plant, though they both, I'm sure, have their uses.

'Black Diamond' had a bit of a head start, in that I'd taken a cutting of it earlier, before realizing that a single cutting of it was going to take forever to develop into a presentable plant. So one of the four plants there already has some roots, though they're not huge, and anyway I probably set them back by pulling the cutting out and sticking it back in perlite again.

Updates as they become relevant.

Random plant event: Aloe x 'Doran Black' flowers

Not the most exciting or unusual occurrence, I'll grant you, and I kind of missed the boat on the pictures: by the time I got to it, the show was half over already. But hey, I'm only one man, and even though it's only January, some of the plants are already starting to speed up growth, use more water, etc.



This happened last year too; 'Doran Black' is apparently just easily bloomed. The flowers are nice enough, I guess, but each individual flower doesn't last very long. Also we've recently seen something awfully similar, though I guess the similarities between Gasteria and Aloe flowers are minor, easily observed evidence for a close genetic relationship between the two plants, which makes this borderline interesting. (At least some, if not all, Gasteria and Aloe species can interbreed, creating intergenic hybrids called "Gasteraloes," which is stronger evidence for the two being related. Gasteraloes don't, to my knowledge, have any particularly huge following or practical use, but now that I've said that I'm sure I'll get the Gasteraloe Society of North America showing up at the blog to tell me they exist, and how dare I not appreciate Gasteraloes as the best plants in the whole wide world, and etc.)



Anyway. I'm actually surprised that we don't have more Aloe and Gasteria species blooming right now at work; I've never been under the impression that any of them were especially shy about blooming. Perhaps the time of year isn't quite right, or maybe we just don't have any specimens that are mature enough to bloom yet. We'll see how things go.

Mister Right (Ficus maclellandii)

I don't know what I can say about Ficus maclellandii:¹ it's one of those few plants that I think is pretty much perfect (others would include Yucca guatemalensis, Haworthia retusa, Euphorbia grandicornis, Anthurium andraeanum, and Aglaonema spp.). This makes for a wonderful houseplant, and kind of a boring writing topic.

I bought my plant almost exactly a year ago, not without some trepidation; I knew that F. benjamina was touchy about being moved, and assumed that the same would be true for F. maclellandii. That was my first pleasant surprise with this plant: I think over the first six months or so that I had it, it lost all of like three leaves. Can you expect the same? Well, not necessarily, but it is supposed to be exceptionally good about leaf retention, and I have yet to see any of these plants have a serious leaf-throwing fit over anything. So there's that.



I haven't really done anything terribly special for mine: it's sort of off to the side of a large north-facing window, and the window itself is close to a white wall, so there's a lot of light there but it's all reflected. The spot in question also happens to be very close to a heat & air conditioning vent, but that is apparently not a problem. My plant really took off this summer, when I moved it from a 6-inch pot to an 8-inch; the extra soil was good, but I give some of the credit to a little bit of incidental root pruning: I also spent some time raking through the roots to loosen up the root ball and permit them to penetrate the new soil I was adding.²

Care is pretty typical for a houseplant, and shouldn't be terribly difficult for anybody: I water mine when I can stick a finger into the soil as far as it will go and not feel anything damp, though it does seem to take over- and underwatering somewhat in stride. Underwatering, I'm told, is more dangerous.

I don’t do anything to supplement humidity, but I have it on pretty good authority that they do like a humid environment, even if they don't insist on it. They are tropical plants, after all.

The biggest pest problem mentioned in association with this plant on-line is scale: I don't know if they're necessarily more prone to scale than to other pests, but I could see how scale might be harder to see: the stems do get woody when relatively young, and the right species could sweep in and set up shop for quite a long time before anybody noticed, by virtue of imitating the natural bumps of the stem. I personally am just pleased that they seem to be fairly resistant to spider mites.

Somewhat bright light is helpful, though I don't think they necessarily have to have it: a lot depends on whether you want the plant to grow or just maintain itself. Actual growth requires, unsurprisingly, brighter light. The situation is similar with temperature: the plant will tolerate high temperatures well, but cold can slow or damage it.

Propagation is possible, but not particularly easy, in my experience: a lot of them have failed on me for each one that's worked out. I suspect that taking a cutting from a woody stem and rooting it in wet perlite would probably work better than what I've tried in the past, just based on the fact that I've had good luck lately with that method for F. benjamina and F. microcarpa. Bottom heat is also nice if you can get it: it's seemed to help some of the cuttings I've tried to start at work.³

The only real issue I've ever seen them have is one that I also can't really explain or fix: we had a couple very tall plants on the center of some of the tables for a while, and they have all, at one point or another, dropped a lot of leaves at once and/or had a bunch of leaves develop dead gray zones of varying sizes. Only the ones on tables did this, it came on suddenly, and it's still going on to some degree though it's happening much more slowly than it was a couple months ago.

My best guess is that they probably either got some blasts of cold air from the top of the greenhouse that they didn't like, which affected them disproportionately because they're the only plants that had leaves up that high, or else they lost leaves because they happened to be in spots where water was condensing and falling on them.

The condensation thing drives me nuts, though it's pretty much unavoidable: we maintain a warm and humid environment in the greenhouse, water condenses when it hits the ceiling, and then when the drops get big enough they fall back to the floor. This would be just fine except that the drops are also freezing cold. Not only is it bad for the plants to be tapped over and over by drops of cold water, if one happens to be under an especially drip-prone spot, but it's kind of annoying for people, too. I can't count the number of times I've been in there doing one thing or another and suddenly had a freezing cold drop of water smack dead center on top of my head. You never get completely used to it.

As previously noted, Ficus maclellandii may, in moments of exceptional happiness, produce figs:




though my guess would be that they're probably not edible, and I'm not sure how far they could develop indoors. (Even if they did develop, they're not likely to produce viable seeds without pollination. Sorry.)

There are a few cultivars, though I haven't seen them personally yet, and I'm a little confused about which are which: as usual, it's tough to sort out which plants are genuinely unique things and which are renamed versions of old things. The various sources I've run across don't seem to agree particularly on any of this either. So. 'Alii' appears to be the default cultivar, probably the one that is pictured here. There's also 'Amstel King,' which is (maybe) a more vigorous 'Alii,' with larger leaves and reddish-colored new growth. 'Amstel Queen' is presumably from the same people who gave us 'Amstel King,' but I couldn't track down anything that explained how it was different. 'Amstel Gold' is said to have yellow-margined green leaves, though the pictures I've seen of it looked to me like the leaves are entirely yellow, save for occasional patchy bits of green along the midrib (example picture #1, example picture #2). I saw a couple references to an 'Alii-Baba,' but no descriptions or pictures, so your guess is as good as mine as to how this might be different.⁴

A lot of these are produced as standards (in fact, I think the only 'Amstel Kings' I've seen have all been standards), which is to say, as a poodley ball of foliage on top of a straight four- or five-foot trunk. I don't mind the look, though I prefer the bushy look of several stems planted together, with foliage from top to bottom. Just personal preference thing. Care would be the same in either case.

I've been an F. maclellandii fan pretty much as long as I've known them, and have only gotten more so as time has passed, but until pretty recently I've seemed to have trouble communicating this to the customers: there's one poor plant there who I think came in at the same time as the one I own, and is still there over a year later. I show it to people, I wax enthusiastic about it, they say it's nice but they want something that flowers, or they don't like the long leaves, or whatever. So maybe it's only the perfect plant for me, and the two of us have a special thing. I dunno. But in any case: very highly recommended.

-

Photo credits: me.

¹ Or F. alii, or F. binnendijkii, or whatever. Though I like the way binnendijkii sounds in my head better, maclellandii appears to be the correct name at the moment. 'Alii' appears to be a cultivar name, of whichever species this is, and – bonus language content! – means "king" in Hawaiian. 'Alii' should not be confused with the weight-loss drug "Alli," by the way, even though the two names look really really similar.
² Some plants handle this better than others, but I do it with anything I’m repotting. Ficus species seem to be the only ones that really take off after this, but most of them at least show no particular ill effects, provided that they're otherwise healthy.
³ The bottom heat isn't there for the benefit of the Ficus cuttings: we've started a bunch of seeds, and they seem to do best with bottom heat. The Ficus just got to play because there was some room left over.
⁴ Attn. marketers: coming up with a clever cultivar name does absolutely no good for anybody if nobody knows what this cleverly-named plant looks like.

Random plant event: Chamaedorea metallica flowers

This has actually been going on for a little while, but I'm only getting around to posting the picture now. The flowers on C. metallica aren't anywhere near as impressive as the flowers from C. seifrizii; I think they must take a long time to develop. The C. seifrizii at work are flowering again, but the flowers are berry-less and a weak-looking, pale yellowy-green, which makes me think that maybe they only turn orange and all that if they've been pollinated.

In any case. This is the second blooming for my C. metallica, which bloomed last winter right after I brought it home. I'd assumed at the time that it had gotten itself ready to go in the greenhouse before I bought it, and that it wasn't likely to bloom again, but then this winter it did, so apparently it just likes it here. (Strangely, the C. metallica at work, and the plants at the greenhouse where I bought this one, are not blooming. I'm not sure whether or not this means anything.)

Last year, I never got anything berry-like from the blooms. Or, well, I did, but they were shriveled from the start, sort of a pretty brick/rust color, and never did anything else. Also they might have been the actual flowers, not berries. Whatever they were, they fell off on their own after a while, and the flower stalk never changed color.

It's not pretty, I'll grant you. But it's still kind of neat.

Unfinished business re: Philodendron x 'Autumn'

So after I wrote that whole post about what a terrible time I was having with Philodendron x 'Autumn,' it goes and does this:


It's not up to the size of the previous growth, granted, but it's a bigger, redder leaf than I've seen in a year, so I'm not going to complain. Was it the implied threats in the earlier post? The public humiliation? Probably neither: I'm inclined to credit the smaller pot I moved it to. But it's nice to know that when reasonable treatment fails you, intimidation and shame are always there to fall back on. Something to keep in mind before you throw in the towel pull the plug flip over the pot.

Urban Cowboy (Euphorbia pseudocactus)

NOTE: Initially, I identified the plant in this post as Euphorbia grandicornis. Then I got a real Euphorbia grandicornis and wasn't sure what this plant was anymore. I've settled on a guess of E. pseudocactus, based largely on the pictures of it at davesgarden.com, but: 1) this could change again if I decide I'm wrong about E. pseudocactus too, and 2) the HTML address for the post still says E. grandicornis. Apologies for any confusion this may have caused. If it helps, virtually everything said herein about E. pseudocactus could also be said, just as accurately, about E. grandicornis.

I mentioned previously, in Euphorbia trigona, that in my quest to buy Euphorbia ammak, I bought two other plants by mistake first. This, obviously, is the other one.

My own plant. (Once again, the file name for the picture has the wrong ID. I'm really very sorry.)
This plant is not widely sold where I live (in fact, I've seen exactly two of them, and one of those was nearly dead), but it appears to be a lot easier to find elsewhere (in the desert southwest in particular, and California especially), judging by the sites that pop up in a Google search. I kind of get the impression that it's even harder to come by in its native habitat of southeast Africa (primarily South Africa and Swaziland), though this is tough to confirm.

A few websites I ran into, more than you'd think would be statistically likely, offer warnings along the lines of this plant isn't for beginners. I suppose there's an argument to be made, there, but I haven't seen any indication that this plant is any more difficult than other succulents from the same family. It needs a lot of sun, reasonable indoor temperatures (I wouldn't go below 50ºF / 10ºC), and water only when the soil is almost completely dry. A quick-draining, very lean soil is obviously helpful in preventing overwatering (and the heartbreak of rot that comes with overwatering). Too much sun, or too sudden of an increase in sun, will cause bleaching and spotting and all-around stress (e.g. if the plant's been inside a shop waiting to be sold for six months, and then you buy it and throw it out into the middle of your yard all summer).

Propagation is said to be pretty easy (I haven't tried it myself), and is essentially the same as what I described for E. trigona: cut off a piece, let it dry in a bright place out of the sun for a few days to a few months (2 weeks was the specific example given here, but I don't think the particular duration of time is as important as the fact that there is some callusing time. Planting immediately after cutting invites rot; waiting too long to plant could leave you with a curved plant (even if it's laying down on a bench somewhere, the cutting will still have a phototropic response: over time, this will result in a tendency for the plant to bow upward unless it's rotated). The site I linked to also used rooting hormone: I'm agnostic about the usefulness of rooting hormone with Euphorbias (or, in fact, pretty much anything else).

This species, and the many similar species of upright Euphorbias with many spines, are often used inaccurately in TV shows and movies to announce "cactus" or "desert" or (very occasionally, in your more symbolic shows) "mean person" to viewers. I'm fuzzy on the reasons why,¹ but it happens often enough to be worth noting.

This is one of the more cactusy-looking Euphorbias, hence the botanical name (pseudo meaning "false," plus cactus meaning "cactus"), though a lot of the African succulent Euphorbias look enough like cacti to be confused with them. So, now might be a good place to go into detail about how the Cactaceae are not Euphorbias, and what's the difference, and why it's not just something botanists and pedants came up with to hassle people about. In the end, hopefully, you'll have laughed, you'll have cried, and you'll have learned a little bit about yourself, and those of you who were really paying attention might even learn a little something about the true meaning of Christmas, though I make no promises.

Let's start with why it's important. The Cactaceae / Euphorbia resemblance is an excellent example of convergent evolution, the term for when two species or groups which aren't terribly related to each other wind up in similar environments, and then solve the problems of those environments in ways that look and function more or less alike.

In the case of Euphorbia pseudocactus, we can see certain obvious adaptations to arid environments: a water-storing trunk, complete lack of leaves to minimize moisture loss via transpiration (some Euphorbia species, like E. trigona, continue to produce leaves, but these are small, pathetic, and apparently pretty disposable), thorns and irritating sap to discourage predation,² a waxy coating to minimize water loss through the stem, a mostly-vertical columnar shape to cut down on sun exposure during the hottest part of the day, and so on. And with a typical cactus, say Cereus peruvianus? Well, we have a water-storing trunk, leaves reduced down to sharp spines to discourage predation, a waxy coating, a mostly-vertical shape, and so on.

What does this prove? Well, not much of anything on its own, but it's indirect supporting evidence for the theory of evolution:³ although there are plenty of indications that the ancestral cactus and the ancestral Euphorbia were very different from one another (e.g. their flowers are not particularly similar, Euphorbias have irritating white sap and cacti don't, cactus spines are modified leaves, and emerge from super-shortened branches called areoles, whereas Euphorbia spines are part of the stem, and some of them still produce leaves), there turn out to be only just so many good ways to cope with the conditions of desert-like environments.⁴

The most impressive photo I could find to show this is here, down at the bottom of the page: not only is there a cactus and a Euphorbia that look a lot alike (I think the Euphorbia might be E. lactea), but they also rounded up a third plant, from the Asclepiadaceae, or milkweed / Hoya family, that looks like the other two, which sort of strengthens the point further.

A very quick and rough guide to telling Euphorbia apart from cacti:

If the spines are paired and at an angle of about 100º to one another, as in E. grandicornis, it's a Euphorbia. Cacti almost always have more than two spines (usually more like eight) at an areole, pointed in every direction.

If the plant bleeds a white, latexy substance when poked: it's a Euphorbia. Cacti usually (I hesitate to say always, though I'm unable to think of any exceptions) have clear sap.

If the plant has conspicuous true flowers (as opposed to nondescript flowers surrounded by flashy bracts, as with poinsettias), it's a cactus. Euphorbia flowers tend to be small, yellowish green, and in clusters.

It's not generally all that relevant, practically speaking, whether you're looking at a thorny cactus or a thorny Euphorbia: they take more or less the same care. But sometimes one wants to know anyway.

The more-cactusy-than-cactus phenomenon that leads Euphorbias to sometimes find themselves in botanically and historically inaccurate TV settings (there was an actual example of this not that long ago, but of course I can't remember the show in question because I didn't write it down immediately: bloggers take note) is a bit like the more-cowboy-than-cowboys phenomenon: Japanese tourists who go to rodeos in cowboy boots and ten-gallon hat, city slickers who wear cowboy shirts and big belt buckles to clubs but couldn't ride a horse any better than a barstool, yuppies who take dude-ranch vacations, etc. I saw this from time to time when I lived in Texas, though not being a cowboy myself, I couldn't say how the actual cowboys took that sort of thing. Probably either stoically, or as the excuse for drunken bar brawls, since those are pretty much the only emotions permitted to cowboys.

Of course none of this is the plant's fault. It's being as authentic as it can.

-

Photo credits: in text.

¹ One of these reasons has to be that some cacti, for example Carnegeia gigantea, the saguaro cactus, are very slow-growing, and consequently hella expensive: about $100 a foot for saguaros. And of course we have to bear in mind that the people who dress movie sets are not generally botanists by training, even if they clearly ought to be.
² It remains something of a mystery to me how insect pests like whiteflies and mealybugs manage to process Euphorbia sap so that it doesn't harm them. Why they do it is less of an issue: obviously Euphorbias have been very successful plants, found all over the world, and any insect that found a way to get past the plants' defenses would have a huge amount of energy, food and water available to it, and that would obviously be beneficial to the species (the insect's species, not the Euphorbia – it'd pretty obviously be kind of disastrous for the Euphorbia). But how do they do it?
³ Anybody interested in the whole evolution / creation "debate" really should know this already, but many people seem not to, so: the word "theory," in everyday usage, means something that's just a plausible guess, as in, "That's just your theory." In science, a "theory" is a whole network of evidence that points to a single conclusion: nobody thinks that gravity is just a plausible guess but the jury is still out. Nevertheless, gravity is still a theory as scientists use the term. Certain creationists have taken advantage of the difference in meanings to misrepresent evolution, and pretty much all of them continue to do so even when it is explained to them that the word means something different to scientists than it does to the population at large. "Oh, but even you say it's just a theory" does not constitute an argument against evolution. If you still need convincing, consider: the big goal in the physics community is to come up with an idea that explains all the different intensities and types of interactions between matter and energy, and this goal is referred to as the Grand Unified Theory of Physics. Physicists do not mean by this that they're in search of some wild but plausible guess: they actually have plenty of those. What they want is a plausible guess which is supported by all the evidence and observation already collected. So if someone pulls this "just a theory" crap on you, know: they're twisting words around on you to mean things that the words don't mean.
⁴ Another support for the idea that these are from different ancestral plants: the Cactaceae are, with one exception, found only in the Americas. The single exception is the genus Rhipsalis, which has one African species (R. baccifera) and two closely related Madagascan species.
Euphorbia, by contrast, has a wider distribution, including some species native to the Americas (the best-known example being Euphorbia pulcherrima, the poinsettia). American Euphorbias tend not to resemble cacti nearly as much as the African ones do; I suspect that this is because the "job" of being cactusy is already taken in the Americas, so Euphorbias have had to find other niches in order to survive here.

Random plant event: new purchase (Aglaonema 'Red Gold')

Found this guy in Cedar Rapids last Thursday: I'm doubtful about my ability to keep it alive for any period of time, but this is the first one of the new, rainbow-of-colors Aglaonemas I've seen, and I didn't really figure I could pass it up, especially since I'm not likely to see another anytime soon.

Word on the street is that the new Aglaonemas are hybrids derived in part from a difficult species, A. rotundum, and that rotundum's need for heat and humidity and bright light has, at least partially, been passed on to its offspring like 'Red Gold.' (Side note: I am not particularly confident of my ID here; Aglaonema cutivar names are normally a labyrinth of contradiction and nuance anyway, and everybody who's trying to sell the red-pink-orange ones seems to have their own names for each variety. The tag in the plant identified it as an 'Aglaonema' and said it came from Twyford International, and Twyford only sells three kinds of Aglaonema, and only one of those three kinds contains red, so, process of elimination. But whether it is actually 'Red Gold,' and whether 'Red Gold' has any actual legal status, I don't know.)

Most of the sites selling these plants, somewhat deceptively (in my opinion) emphasize only the easy-care qualities of Aglaonema in general, and fail to address whether these other varieties might be more problematic. We will see. The advice I have gotten is to give it more heat, light, and humidity than I would the average Aglaonema. Light is easy; heat and humidity are nearly impossible, especially right now: our high temperature here yesterday was the nearly unprecedented 1ºF (-17ºC), and the temperatures for the forseeable future are warmer than that, though not by a lot. The apartment stays warm enough, but there are still unpredictable and mobile cold spots here and there.

Anyway. On to the gardening porn:

(at the store)

(The one I purchased)

(Leaf close-up)

Some of you will have been expecting more dramatic redness than this. In fact, the whole purpose of the close-up picture is so you can see that no, there really is some red-orange going on. I don't know why there's not more than this, but the greenhouse it was in when I bought it was actually, as greenhouses go, very dark, even during full sun: they have the roof shaded (whitewashed?) so much that I'm kind of surprised that anything grows in there. (More confusing: the heavily shaded greenhouse is where they keep the cacti and succulents, even though they have at least three more greenhouses with unshaded roofs available, greenhouses which aren't even, for the most part, being used right now. I can appreciate not wanting to move a bunch of spiny plants back and forth every time the season changes, but some of them have been there long enough to show signs of etiolation. It's a mystery.) Possibly the plant will redden up when it has more light. We'll see how things go: it'd be cool with me if that's as much color as it ever showed, so long as it would also be easier to keep: I noticed and liked the stripey pattern to the leaves before I noticed the red.