Here's yet another plant that doesn't really catch any breaks in the naming department, just like Chlorophytum comosum. Sansevieria trifasciata is most commonly known as "snake plant," because the leaves are long and thin like snakes, and have irregular banding on them that sort of resembles the patterns on certain snakes, and that's okay. Not the most beloved of animals, but no big deal. It's also called "bowstring hemp" from time to time, owing to its past use in making bowstrings for African archers. (One source said Indian, not African. Maybe it's both. Maybe both of them are wrong. This is why using the internet for research can be dangerous.) Which is okay, too, I guess, though that's a little confusing because it's a totally different plant than hemp, and I think that most people of the world have moved on to guns anyway, not bows and arrows. Still, I suppose it's important to note its military past: I can't think of many other houseplants that have ever been in the service.
But the common name that concerns me here is the name "mother in law's tongue." In the last couple weeks, I've seen two different sites get this confused with another plant, due to the common names of each. Since the misinformation in question is potentially dangerous to people, and since it further makes my point about common names being problematic, a topic I pound on relentlessly at every opportunity, I'm going to lead with an explanation of what the mixup has been.
There are two plants that have mothers-in-law in their common names. Dieffenbachia spp. are (very occasionally) called "mother-in-law plant," and Sansevieria trifasciata is (a little more often than Dieffenbachia but still not very often) called "mother-in-law's tongue." The Sansevieria version is a reference to the size and shape of the leaves, plus more than a little bit of metaphor.1 I think if we really wanted a description with strict accuracy, we'd do better with a common name like "Gene Simmons' tongue:"
Or possibly "giraffe's tongue," which is a little closer still, as far as size and color goes:
I mean, look at that shit.2 I'll leave these out there just in case the internet wants to take up either suggestion. Realistically, I suspect the mothers-in-law still have it, but I like my ideas better.
The Dieffenbachia version is more sinister: Dieffenbachia spp. contain gazillions of tiny calcium oxalate crystals, which are sharp and are driven into the tongue, throat, and cheeks when a stem is chewed. The leaves and sap also contain these crystals. The suspicion last I knew was that Dieffenbachia also contained a second chemical of some kind or another which makes the whole business more painful, though I'm unclear about whether or not anybody's ever actually identified one or just thinks something else might be in there. Maybe I'll know by the time I do a Dieffenbachia profile.
In any event, chewing on a Dieffenbachia stem or leaf will drive bajillions of little needles into your sensitive mouth parts, possibly also with an extra chemical kicker to make it more painful, and your mouth and throat will react to this by swelling up. If your mouth swells, this is probably going to be painful, but it's not likely to be any huge or permanent deal, not really. If your throat swells, on the other hand, we have a problem, 'cause a person has to use his/r throat on a pretty routine basis, for swallowing and breathing. That does get life-threatening, potentially. Even if your throat doesn't swell shut, you're still going to have trouble forming words or getting them out, which is the (kinda mean) motivation for the name "mother-in-law plant" (i.e., plant you want to feed to your mother-in-law) and the more frequently encountered common name "dumb cane."3
So I hope that cleared everything up. I'm told that a lot of the reason for the misunderstanding is that someone at this link, at davesgarden.com, put this on-line and so now when people check davesgarden.com for info, this is something they see, and it gets passed on because it's scary, and after all what if it's true? This is the first houseplant urban legend I've ever run across, so it's interesting in that way, but research and experience tell me that urban legends get passed on a lot faster than they get refuted (check snopes.com sometime if you don't believe me: there's stuff on there that's been circulating for forever), and I found similar stuff on other Sansevieria pages at davesgarden.com, so I doubt that all of them are ever going to be corrected. So expect to be hearing about this for the next twenty years.
The same davesgarden.com thread I linked above also contains misinformation about Kalanchoe daigremontiana (now Bryophyllum daigremontiana, *sigh*), or "mother of thousands," though that misinformation, at least, got corrected downthread. Sansevieria trifasciata is poisonous, at least to cats (unsure about dogs or people), but it doesn't paralyze anybody's vocal cords. Dieffenbachia doesn't paralyze anything either, of course, unless paralysis has been redefined to include swelling.
Sorry that took so long. At least you got to see Gene Simmons.
There are many species in the genus Sansevieria, but only a few are commonly grown as houseplants, and Sansevieria trifasciata is the most common of those by miles. Time, chance and greed have given us a number of cultivars, and new ones are coming along all the time. (There is excellent Sansevieria eye candy here: if you can't get the link directly, go to "products and services" and click "new products." I want 'Onyx Black' something fierce. Another fine site for your Sansevieria porn needs is this one.) The most common cultivar is 'Laurentii,' which is a tall plant (to five feet) with yellow-edged leaves. A few people claim that 'Laurentii' occurs in the wild (Sansevieria trifasciata is native to west Africa, Wikipedia says, though the growers' guide says Sansevieria the genus is found in Africa and Asia. Aggravatingly non-specific about S. trifasciata, but I think because of this we have to allow the possibility that it could be from somewhere else, or maybe more than one place); this seems unlikely to me, because it seems like it would be disadvantaged (less green photosynthetic area, so less energy, and leaf sections, if they sprout, revert to the nonvariegated plant: we'll get to why and how this works much, much later), but it's not impossible, I suppose.
Sansevieria trifasciata is a common houseplant because it is so very easy to grow. Now, there are betterer and worserer ways of growing it, but if your goal is just to keep it alive, there are really only three rules to remember, and one doesn't count:
1. Do not overwater this plant, and really, really don't overwater this plant in the winter.
2. Do not expose it to cold (below 35ºF / 2ºC).
3. Never, ever feed it after midnight.
Well, okay. That last one is actually from the movie Gremlins. Not actually bad advice, though.
For best results: water when the soil is almost completely dry (in summer) or not at all (winter).4 Bright indirect light is good, though any level except full sun (which may bleach leaves a bit, especially if it's also hot) should be okay. The plants are more or less indifferent to humidity levels5 or temperature (as long as it's above freezing and all). Well-draining soil is very important for all plants, but especially so for this one; if it sits in wet soil for too long, it'll rot.
Pests aren't usually a problem. I think I brought in some whitefly on the 'Laurentii' pictured above (story at the link), but it wasn't hard to get rid of and I'm not positive about the ID. (UPDATE: I'm pretty sure, as of January 2010, that it wasn't whitefly. Though I have no idea what it was, if not whitefly.) They're also supposed to have the occasional scale or mealybug situation, but they're not known for anything in particular, like some plants are.
They are supposed to be somewhat heavy feeders, from what I've read, and I suspect that this is a big part of a common Sansevieria problem: on a lot of older plants, you'll see the leaves flopping over the side of the pot. The leaves are still alive, and the plant continues to grow, but it no longer holds itself upright. I think lack of fertilizer, lack of light, and soil being washed away from the top of the root ball all play a part in this. Limp leaves will remain limp, but if you feed the plant, give it a little new (well-draining!) soil on top of the roots, and move it to a brighter spot, the new growth should do a better job of holding itself up. Can't say I've done this myself: that's just a guess.
Sansevieria trifasciata also don't tend to develop incredibly deep root systems. More than once, people have brought plants in to work for repotting, in giant pots twelve or more inches deep, and then when I've slid the plant out, there were no roots in, like, the bottom eight inches of soil.6 There's not really a good way to handle this: if you put the plant in a shallow pot, it'll be top-heavy and uproot itself all the time; if you put it in a deep pot, you risk rotting it out because of all the heavy, water-retaining soil under the roots. The best compromise I can suggest is, get a deep pot, and plant it lower than you usually would. Leave no more than a couple inches of soil under the root ball. It doesn't solve the whole problem, but it avoids the worst of it, and the edges of the pot will also help support any plants with a tendency to fall over.
The root systems aren't deep, but they are active little guys. (Shallow but busy: sorta like Keanu Reeves, twenty years ago.) The plant will reproduce itself via rhizomes, which are, for all practical purposes, underground stems. The rhizome travels a certain distance and then throws up a new rosette of foliage: given enough time, a single plant will fill its pot this way. (The photo immediately above is sort of a good illustration: the lighter-colored new growth on the far left of the pot is such a sprout.) While this is great if you're wanting to propagate a plant, it's not such great news if you don't: a rhizome that's frustrated for long enough can place enough pressure on a pot to break it open, all at once, usually on a day when everything else is also going wrong and you don't have time to clean up after a plant that's delirious with its first taste of freedom after years of confinement. Plastic pots, though not as good for the plants (because water can't exit the pot through the sides, so the soil stays wetter longer), make this situation easier to monitor, because they visibly bulge and stretch, though it doesn't come up very often in the first place.
The plant's tendency to spread by runners has made it into an invasive weed in places, mainly in islands in the South Pacific where it has been deliberately cultivated. It's also a problem in Hawaii, Australia, and Florida, but then, what the hell isn't a problem in Hawaii and Florida, right?
Propagation is easy, but there's a big catch. The easiest way to do it is to separate rosettes by cutting the rhizomes that separate them. Each rosette can be planted up individually, and, given proper care, it will begin to fill out its pot relatively quickly. The (kinda obvious) down side to this is that you can only get as many new plants out of this as you have rosettes in the original plant, at least until the divisions decide to make more.
There's another method: leaf sections. You take a long, healthy-looking leaf, cut it into pieces about two to eight inches long7 (I'm planning on doing this soon for another post, with pictures and stuff, though it's not so complicated that you couldn't just read about it and then do it for yourself), plant them right-side up in a rooting medium of your choice (ordinary potting soil should work on its own, though when I try this, I expect I'm probably going to amend the soil with sand or perlite), and keep the medium just barely moist until you see shoots appear from the base of the leaf. At this point, the original piece of leaf is no longer necessary, and can be cut away from the shoot, which will support itself after that. At least one site I ran across claimed that the leaf section could be re-used, and another shoot made from the same leaf section. I don't know whether this is true, but I wouldn't be surprised.8
Oooookay, Mr. S. Still not seeing a catch, though.
The problem is that certain kinds of variegation will reproduce from cutting apart rhizomes, but won't reproduce from planting leaf sections. So, if you want to, you can take a leaf of 'Laurentii' and cut it up and plant the sections and get new plants, but the new plants will lack the yellow variegation on the edges of the leaves. Other kinds of coloration will reproduce this way: 'Moonshine' / 'Moonglow,' for example, is supposed to retain its coloration when propagated from leaf sections, as will the other silver-gray cultivars (I'm using this link as an authority.), and plant habit also reproduces (as for example with Sansevieria trifasciata 'Hahnii,' a low-growing sport with a flatter rosette and much shorter leaves), but 'Laurentii' and 'Bantel's Sensation' (pictured below) will revert to plain green plants with the same habit as the variegated parent. I have not yet seen a definitive answer on whether or not the black cultivars ('Black Robusta,' 'Black Coral,' 'Black Gold') revert to a lighter color when propagated from leaf sections, but I suspect not, based on my incredibly limited understanding of how this all works (though 'Black Gold' almost certainly loses the yellow edges, just like 'Laurentii'). The planned leaf-section propagation is mainly to find out if the silver-gray plants, or the very dark green plants, really will retain their unusual coloration using this method.
[UPDATE: Karen715, in comments, says that 'Moonglow' doesn't come true from cuttings but reverts to the standard Sansevieria coloring of dark green stripes on light green leaves, though the habit remains the same. This has its own cultivar name, 'Robusta.' A test to see what 'Silver Queen' does will be underway in a couple days, as soon as I get a chance to cut up and plant a leaf.]
I know, cliffhangers suck. But so does trying to read 5000 words at a sitting. You know there are better things you could be doing with your time. I promise it'll be worth coming back for.
(Link to Part II of Sansevieria trifasciata)
Photo credits: mine, except as otherwise noted.
1 Without the metaphor part, one would assume that when you become a mother-in-law, your tongue magically becomes several feet longer, green, and pointed. My understanding is that, historically, this almost never happens. Maybe once.
2 As a child, I found Gene Simmons' tongue, and KISS in general, sort of alarming and terrifying, though this had less to do with the tongue than the evangelical Christian environment in which I was being raised. Now, I look at that picture and think, stop! You're trying too hard! Also: giraffes are cute.
3 Pet peeve: kids today seem not to know the word dumb can mean "mute." To them, dumb = stupid, end of story. Since there is a printed card near the Dieffenbachias with the name "dumb cane" prominently displayed, and since we're in a college town and consequently have a lot of customers who are nineteen, look twelve, and think at an eight-year-old level, I get to hear somebody say "dumb cane" to somebody, followed by Beavis-and-Butthead style laughing, every couple weeks or so. Yet another reason to hate common names. Though for the record, I loooooove Beavis and Butthead.
4 It's actually usually recommended that you water at least once during the winter, and I've been watering my smaller plants monthly this winter so far. But if you're not confident about being able to gauge when it needs water, leaving it dry is always the safer course of action. At least until spring.
5 I ran into a few sites that claimed that Sansevierias like humidity. It's possible, I suppose, but I've never seen anything that made me think they give a damn one way or the other. Even if they did like high humidity, I don't think they get it in their natural environment, so it's certainly not worth the time and effort to try to increase the humidity for this plant by itself.
6 Which raises questions. Is my responsibility to the customer, the store, or the plant? The store gets money if I do the repotting, and doesn't if I don't. The plant could die if I do the repotting, and won't if I don't. The customer may or may not change his/r mind about the procedure if I ask them, and the customer may or may not be upset that his/r judgment is being questioned, and the customer may or may not blame the store if the plant dies because I didn't say something about this to somebody. So far, the tendency has been to try to contact the customer and explain the reservations, and as far as I can remember, this has not yet resulted in anybody changing their minds about anything. Though it may, soon, get me to change my mind about whether or not I bother to call people anymore.
7 Longer sections are said to produce more shoots per section, and are also supposed to produce shoots faster. The big disadvantage, obviously, is that you're not going to be able to get as many long sections from a leaf as you could get short sections. The typical recommendation, which I assume is where one maximizes the number of potential new plants, is supposed to be about 4 inches (10 cm).
8 Off-topic, but one of my co-workers tells me that his grandmother, who had hundreds of African violets (Saintpaulia spp.) at any given time, was able, with one lucky leaf, to produce twenty-six plantlets from a single leaf cutting, by doing the same kind of thing: when the new sprouts came up, she would cut off the petiole of the original leaf and replant it. I don't doubt that this is true, and mention it solely to marvel at the dedication required to do something like that. Whether a similar cut-and-replant procedure would work for Sansevieria, I have no idea, but I wouldn't be surprised if you could get a second batch every now and again. Maybe more.