Scarecrow (Cryptanthus cvv.)

(This is part 5 of the Wizard of Oz plant profiles.)

In the movie, the Scarecrow doesn't get much respect. Had he not spoken, Dorothy would have walked right by him. He can't intimidate the crows at all. He gets set on fire once, and he's apparently brainless to boot. Not a curriculum vitae that inspires confidence.


Similarly, Cryptanthus spp. aren't high-profile in the houseplant world. We sell a few, occasionally, but customers walk by them all the time. This isn't particularly surprising: it's difficult to find a suitable display area for small plants. (Dionaea muscipula, venus fly-traps, pose similar issues for retail, but they're actually worse, because they have fairly specific cultural needs as well, so we're limited as to where we can put them before we ever consider whether the customers can see them.) When we do have a good spot for them, they tend to sell well, though they're never going to be a bread-and-butter¹ plant.

One gets the impression, though, that Cryptanthus don't necessarily want a lot of people knowing where they are: they kind of work at being inconspicuous.^{2, 3} The varieties people grow as houseplants are terrestrial⁴ and small, forming low rosettes on the ground a few inches across. (Though there are larger varieties, and I've seen plants maybe a foot in diameter for sale around here before -- at Wal-Mart, if I recall correctly -- so just because it's a Cryptanthus doesn't mean it's going to be tiny. The smaller ones, in my experience, do seem to be more available than the larger ones -- I really have no idea whether it's because they're easier to produce, easier to ship, more in demand, or hardier, but it's surely got to be at least one of those things.) Gray, green, brown, black, and white are common leaf colors, and some of those can be very interesting (especially the brown, which is a really unusual color for a living plant), though the better sellers tend to be red, coral, or pink.


Different sources give different numbers of species: this page from the Florida Council of Bromeliad Societies (FCBS) lists thirty-nine full species in the genus Cryptanthus, and 404 named crosses or sports or whatever; I'm inclined to go with their numbers because they seem kind of obsessively (in the good way) interested in precise identifications. On the other hand, "Dr. David Benzing, bromeliad expert extraordinaire, recognizes 42 species."⁵ So who knows. I confirmed some suspicions about what plants I had on the FCBS site, though I failed to identify everything I didn't know already. (They probably do have pictures of the remaining unknowns: on the other hand, life is too short to spend it looking at Cryptanthus pictures.)

As best as I can determine, all Cryptanthus species are native to Brazil, though the specific habitats in question are fairly diverse (dry and shady, on top of rocks, salty wet coastal spots), and the internet is divided about whether they're primarily from southern Brazil or eastern Brazil.

I can't say all Cryptanthus varieties are suitable for growing indoors, since I haven't met but a fraction of them, but any that you're likely to find offered for sale should be. They should also be safe for people with children and pets: to be best of my knowledge, they are not toxic (bromeliads aren't, in general: in fact, I don't think I could name a toxic bromeliad if my life depended on it⁶). They do try to be scary: every Cryptanthus I've seen so far had small, pointed serrations long the leaf edges, but they're too soft and small to do any actual damage, unlike certain other bromeliads I could name; I don't know what the Cryptanthusesuses⁷ think they're deterring.


This is also, I think, the only houseplant I've ever lit on fire.

It was accidental, if that helps.

(Er, semi-accidental, that is: I meant to light something on fire, just not the plant.⁸)

Provided that you don't light them on fire, and maybe even if you do, Cryptanthus are pretty easy houseplants. I've never had any of mine really do anything objectionable (perhaps because they fear immolation if they do?): no pests, no rot, no massive shedding of leaves. I find them pretty much indestructible, though they have a reputation for being semi-difficult, and I realized as I was writing this that I've been doing a lot of stuff "wrong" with mine, and they're still fine. There have been a few failures to propagate, but aside from that, you know. So I don't have a lot of confidence in my rating, above, as it applies to other people. Your mileage may vary:

LIGHT: Cryptanthus spp. usually require some direct sun, though not necessarily a whole day's worth. One of the ones I have now is in a west window and has done well there for a while, though it is turning white instead of pink at the moment, because we've been having a dark winter so far; another is near a very bright artificial light (one marketed for Seasonal Affective Disorder⁹ which has been bright enough to fool cacti and crotons), and it's maintained color and done well in that spot. Less light won't necessarily kill your plant, but it may make it change colors: white instead of pink, or green instead of brown, and new growth may be weak. Too much light can burn them, but this is not likely to happen to any plant kept indoors so I wouldn't worry about it if I were you. I mean, really, acetone fires are probably a bigger danger.

WATERING: In my experience, Cryptanthus are not especially picky about when they get watered. I personally let mine get nearly but not completely dry between waterings, which winds up being approximately once a month for the one in a 4-inch pot and once every two weeks for the one in a 3-inch pot.¹⁰ That said, most of the websites I ran across recommend even moistness, with no drying out (some of them insisted on this, even), and the plants at work tend to be more on the wet side than on the dry side, so I'm not sure what to recommend here. I suppose I'll go with the experts, and start watering mine more often, but you may be able to get away with growing yours drier if you find you really have to for some reason. They do have certain water-conserving adaptations, see below.



TEMPERATURE: Not really that big of an issue: most varieties will tolerate any temperature found in the home (anything between 32-100F / 0-38C), though they're happiest in the 60-85F (16-29C) range, like most people. Plants kept in warmer conditions will need water much more often, just so you know.

HUMIDITY: Does need to be high for the plant to do well and grow continuously, though it doesn't seem to be completely unreasonable about it either. I guess. We don't do anything special here, but as I've noted previously, the apartment's humidity situation is not normal (we generally run between 40-60 percent at all times; the windows are fogged up all winter long), so if you have a normal home, especially if you live in a climate with particularly dry winters, a terrarium might not be a bad idea. Or at least a humidifier or pebble tray or something.

PESTS: I've never seen any pests on a Cryptanthus, nor did I run across anybody else warning about anything terribly specific. Mealybugs and scale are really the only pests I could imagine posing much of a problem. Plants that are kept too wet for long periods can rot out, and rot is a fairly routine problem with trying to root offsets, see PROPAGATION.



GROOMING: Very nearly zero. Your results may vary, but it's a pretty rare occasion when mine so much as lose a leaf.

FEEDING: One of mine got by for a year or better without fertilizer before I finally gave it a little bit. I don't think that it's a particularly urgent need, though. (Willing to be corrected on this point if anybody knows differently.) Bromeliads in general are poisoned by copper and boron, so avoid fertilizers containing these if you do intend to fertilize. Unlike most bromeliads, Cryptanthus do not absorb significant nutrients through their leaves, so foliar feeding is not going to be useful. The abovelinked bromeliad-chicago.org site recommends a slow-release fertilizer in the soil, along with occasional very light fertilizer delivered in the water. I did eventually give mine a slow-release form, at less than the recommended strength, and that's done okay for us so far.



PROPGATION: A Cryptanthus will flower the same way a lot of bromeliads do, with a bunch of bracts to begin with, and then true flowers popping up out of the bracts for a period after that. The true flowers aren't especially interesting - they remind me of Tradescantia flowers more than anything: three petals, white - and last only for a day at a time (also like Tradescantia). I don't know what happens next if a flower has been pollinated. I mean, seeds, I assume, but I've never seen the process, so I can't tell you. But even if the plant has not been pollinated, this is usually the signal for the plant to begin producing pups.



In the varieties I've seen so far, the pups usually pop out near the top of the plant, from just inside the spots where leaves join to the main stem:


But some plants will also produce pups from beneath the soil, as well, just to hedge their bets, I suppose:


The thing I find fascinating about the pups is, they're only very loosely attached to the plants, and this attachment gets looser as the pup develops. So once a pup is a good size (the usual recommendation is 1/4 the size of the parent plant), rock it back and forth gently, and it will detach. I expect that pups not deliberately detached by a human would probably still eventually push themselves off the parent plant: in nature, they roll a short distance away and then root.



This is the part that gets tricky for indoor growers, because a plant that's buried too low, or kept too wet, will rot rather than rooting, and even if you get it all right, rooting takes a long time. There's no secret perfect way to do this as far as I know, but so far, the most effective way I've seen is what WCW did with some during this last summer and fall: she put sphagnum moss in a clay saucer and stuck the offsets in the moss. We watered the moss occasionally, the Cryptanthus formed roots in a few months, and then we moved them to regular soil. I've also tried sticking them directly into soil, which has worked better at work (so far) than it does at home, where it sometimes works and sometimes doesn't. I've tried vermiculite at work, too, but too recently to report on how well that worked.

It seems like a lot of work, to me, to go to all the trouble of producing a pup and rolling it off the mother plant without any assurances that it's even going to land right-side up, but I suppose we don't expect serious planning from the Scarecrow.


And now, because the "brainless" Scarecrow was actually the smartest one of the group (according to the book -- not so much the movie), here are a couple odd little Science! tidbits that were new to me, as reported by killerplants.com:

1) They conserve water by taking up carbon dioxide primarily at night, the reverse of most plants.¹¹ Most plants take in their carbon dioxide during the day because it makes sense to take up the raw materials at the time you're going to be using them, but some or all species of a lot of houseplants, including the genera Cryptanthus, Crassula (jade plants, among others), Ananas (pineapple), Euphorbia, Hoya, Zamioculcas, Agave, Aloe, Gasteria, Sansevieria, and Yucca, take up carbon dioxide at night, combine it with a compound in the cells called pyruvate, which a couple of steps later turns it into the four-carbon acid, malic acid.¹² The malic acid hangs around until morning, when the plant splits it back into carbon dioxide (which is then used in photosynthesis like any other plant would do) and pyruvate. (Oh come on, this isn't that bad; you can follow this.) The pyruvate is then free to store another round of carbon dioxide the next night. This process is called Crassulacean Acid Metabolism, in a rare moment of scientific lucidity, because it was first discovered in the Crassulaceae, it involves acids, and it's a type of metabolism. Usually it's abbreviated CAM.

But, you may be saying, why, Mr. S? Why would a plant bother to do this? It's not like there's no carbon dioxide to pick out of the air during the day, is there?


Well no. But -- do you notice anything special about the plants that do this? Anything, in particular, about the leaves of plants that do this?

CAM is yet another adaptation for plants that live in hot or dry (or both) environments, to minimize water loss. Most of the plants in the above list have thickened leaves, small leaves, or no leaves, most of them have a waxy coating to reduce the amount of water they lose to evaporation, and they use CAM to keep from losing water through their pores when they're trying to collect carbon dioxide. Instead, they take up carbon dioxide at night, when it's cooler and the relative humidity is higher. If it's very dry, they might still lose water that way, but when water is hard to get, anything you can do to conserve it and use it more efficiently is a good thing.

Cool though all this is (Oh my god! You learned a tiny amount of biochemistry! Pyruvate! Wheeeee!), I'm left a little puzzled. It's fine if water conservation through CAM is part of the Cryptanthus experience, but -- what for? They don't have especially thick leaves (at least not as compared to a Hoya or a Crassula: I suppose they do have thicker leaves than most bromeliads), and if you listen to people, they apparently demand humid air and moist soil. So what's the point of requiring lots of moisture around and resorting to CAM to conserve water? Why conserve it if it has to be all around you anyway? Why demand large quantities of something around you if you don't even use it all that fast?

[crickets]

Very well then.


2) The other item of interest is about chromosomes. While people have created a lot of hybrid Cryptanthus varieties, the genus as a whole is also, like some other plants (notably Syngonium podophyllum and Hedera helix), prone to throw out new sports all on its own, every once in a while, and there's an interesting possible reason for this, assuming that the above link, and Wikipedia, are trustworthy, which . . . well, I know. But I'm going to tell you anyway.

Most bromeliads, as I mentioned in the Vriesea splendens profile, have 25 pairs of chromosomes, or else numbers very close to 25 or a multiple of 25 (24, 25, 26, 50, 100, etc.). All Cryptanthus, though, have only 17 or 18 pairs, at least the ones anybody's counted so far. This is a little weird, but they still seem to more or less function, and it's not necessarily the case that they're actually missing anything much: on evolutionary timescales, it's not unheard of for chromosomes to link together or break apart in a stable way, so chromosome number can go up and down. If you think of chromosomes as books, this is like somebody taking Moby-Dick and The Scarlet Letter (the two original chromosomes) and printing a version that has them both bound together: all the same words are there, but instead of one large book and one small book, you now have one single very large book that changes stories in the middle. (The same analogy holds for increases in chromosome number: imagine a printer declaring that Moby-Dick was too long to bind in a single book, so they split it in two and publish it as two volumes instead.) Such big changes to chromosome structure are generally dead-ends, because it only gets passed on if you can find and mate with another organism that's rearranged their library in the same way, or at least a similar way, but that's a long story and this profile is plenty long already.

Not that it's not possible that Cryptanthus might actually have lost information, too. I ran across a scientific paper about the Cryptanthus chromosome number problem, that noted that yes, there were theories about why they're different from all the other bromeliads, but of course you have to be a paid subscriber to actually read the damn paper, so I don't know what the theory is. But really, there are only three basic possibilities: either the information contained in seven or eight pairs of chromosomes got lost along the way, and is no longer in the Cryptanthus genome (the library no longer has a copy of The Red Badge of Courage), or it got moved somewhere else, most likely by two chromosomes linking up to form a new, much longer one (the Moby-Dick-Scarlet Letter nineteenth-century SuperSaver volume), or both. This sort of thing happens all the time (on evolutionary timescales). But either way:


The secret to Cryptanthus variability is thought to be B chromosomes. Not X chromosomes, not Y chromosomes, not even Z or W chromosomes, but B chromosomes.¹³

You could think of the B as standing for "bonus." B chromosomes aren't required for the organism that has them to live, and if you have them, it's not terribly important how many of them you have. In fact, most Bs don't even code for anything and are never read, and sometimes one part of an organism might have them and another part of the same organism doesn't. They're also not necessarily transmitted to descendants, though when they are, the descendant usually winds up with more copies than the parent had, which is quirky. What B chromosomes can do is get in the way, though, which can make the plants that have them malfunction in ways affecting their fertility or appearance, which would lead to sports. Other organisms can be really variable without necessarily having B chromosomes, so I'm not certain that the B chromosomes are the whole ball game here. But it's at least a likely partial answer.

But so there you have it. Voila: Cryptanthus.

I suck at endings.

-

Photo credits: Scarecrow photo via shawnnacox.com; the remainder are my own.

¹ "Bread-and-butter" is the work idiom of choice for the plants that pay the bills, as opposed to the plants that make mr_subjunctive, WCW, and the other plant geeks happy. Dracaena marginata, Codiaeum variegatum, Philodendron hederaceum and the self headers^a like 'Autumn' and 'Moonlight' -- these are bread-and-butter. Stuff like Pseudorhipsalis ramulosa and Neoregelia are what make WCW and me happy, and you can tell the difference by the way we have failed to sell any of them to anybody but WCW and me. There is, fortunately, a little bit of overlap between the categories. There are also a few plants that are neither, but we don't talk about them. Shhh.
      ^a ("Phil O'Dendron and the Self-Headers" would make a GREAT band name, by the way.)
² Which means they're probably going to be upset with me for drawing attention to them.
³ This is reflected in the botanical name, which almost every search result for Cryptanthus will tell you means "hidden flower."
⁴ The entire genus is terrestrial, as far as I can tell, though there's a species or two that grow on rocks rather than in soil, which depending on your perspective may or may not count as terrestrial.
⁵ Someday, I hope to be an "expert extraordinaire" at something. Also a supervillain, as I believe I've mentioned previously. Not sure which title should go first on the business card, though. "Expert extraordinaire, supervillain" seems to scan better, rhythmically. EXpert exTRAORdinaire SUPervillAIN. What is that? Trochaic? Ananpestic? (See kids? You never know when you're going to need this stuff in real life.)
⁶ Of course, if my life depended on it, I probably couldn't name a non-toxic one either: sometimes I can think quickly under stress, and sometimes I cannot. It's hard to imagine a situation where my life would depend on naming a toxic bromeliad, anyway. I'm only very infrequently held captive by plant-obsessed supervillains/-heroes, and so far, when I have been, they've been more interested in finding out why their Spathiphyllum is going black than in learning about obscure bromeliads. (A: overwatering. Nine times out of ten.)
⁷ I'm not sure what the plural of Cryptanthus should be.
⁸ The story, mildly altered from a version I told at Garden Web some time ago:
I was kind of a pyro at the time, with access to acetone (= cheap nail polish remover; the expensive kind is usually ethyl acetate) as the result of being a chemistry undergrad. (Acetone will dissolve almost anything, and is relatively cheap and nontoxic, so we used it to clean glassware and stuff. Plus it dries quickly, because it has a lowish boiling point.) This had previously been used to, for example, light flat tennis balls on fire and throw them out of my (4th-floor) dorm window, set brief but impressively large fires on the (ceramic-tiled) hallways, dissolve styrofoam, and so forth. I'm not saying any of this was a good idea, please note, but it seemed like one when I was however old I was (19? 20?).
The dorm rooms had a sink in a corner, with a mirror above them. (I'm trying to recall whether it was just a mirror or a whole medicine cabinet, and drawing a blank. Probably a medicine cabinet.) For some reason, I had the plant sitting on the sink -- possibly I'd just watered it, possibly I'd run out of room for plants elsewhere in the room.
If I'm remembering correctly, the idea was to spray acetone on the mirror, and then light it on fire, so the fire would be reflected and look bigger and brighter and so forth, but I didn't take flammable vapor and dripping into account, so I kind of lit the whole sink area on fire, including the plant, for a few seconds. I do not recall whether the fire looked bigger/brighter, because I realized midway through that I'd set my plant on fire and was distracted by that.
Hence, accidentally lighting plants on fire. The incident scared me enough that I believe it was the end of the acetone period, though I was still a pyro for a year or so after, though that was as close as I ever got to damaging anything of any actual value. The pyro thing stopped at about the time I came out of the closet: draw whatever conclusions seem appropriate.
Just to underline: this was not actually a good idea. Your results may vary. Do not attempt.
⁹ Which I do not have: the husband has at times thought that he did, which is why we have the light. It's possible that he still has SAD, but one of the side effects of having plants covering every available surface is that there also has to be a lot of light, so I don't recall him mentioning this last winter. I, if anything, have the other SAD: the one where you get depressed / irritable / apathetic in summer, though I figure that's got to be a heat thing, more than a light thing.
¹⁰ Interval periods given for comparison purposes only. I do not actually water my plants on a fixed schedule. Do not water your own plants on a fixed schedule: not only is it usually bad for the plant, it's sinful.
¹¹ If you're one of those people who are worried about your plants suffocating you to death at night, when they absorb oxygen and release carbon dioxide, and you don't trust me when I tell you that this is not something you should be worried about, you might consider buying some of the plants from this list, since they can take up the carbon dioxide from the other plants at night and in theory everything should balance out, then. Or you could just believe me, based on how you've not suffocated in your sleep every night of your life so far. Your call.
¹² From malus, Latin for apple. You'd recognize it if you tasted it, as it's one of the main components of sour edibles like green apples, SweeTarts, grapes, Jolly Ranchers, etc. For this reason, supposedly the leaves of plants that do this taste sour in the morning (when malic acid storage is at maximum) and sweet (or at least less sour) in the afternoon (when most of the malic acid has been metabolized). I'm skeptical about this myself, but I'm not going to start eating the houseplants twice a day to check.
¹³ (Someday, we're going to run out of alphabet, and then the biologists are going to be fucked. . . .)