Friday, April 24, 2009

Houseplant Toxicity Week: Part 7 (Unknown / Could Not Determine Plants, and Conclusion)

If you have landed on this page because you are concerned about a child or pet who has eaten a plant, seek emergency medical help.

In the U.S., you can call Poison Control at 1-800-222-1222 (for children), the ASPCA at 1-888-426-4435 (for pets; $60 consultation fee applies), or the Pet Poison Helpline at 1-800-213-6680 (pets; $35 fee applies)
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Part 7 of a seven-part-and-two-appendix series. (Part 1) (Part 2) (Part 3) (Part 4) (Part 5) (Part 6) (Appendix 1) (Appendix 2 - Index)

These are the unknown/could-not-determine plants. For these, either I couldn't find enough information to determine whether they were harmful, or I found information but it was contradicted by other information that seemed equally good. (I think the best celebrity analogy would be Oprah Winfrey: is she good? Is she bad? All we can really agree on is that she's very powerful. Martha Stewart would work too.) In any case, I've included my best guess for each plant, but that's all it is, is a guess, and I am almost certainly wrong about some of these, possibly very wrong. With any luck, this list will dwindle over time, as more information comes in and I can move some of these out of here.

Adiantum spp. (maidenhair fern) I didn't see any specific references to Adiantum. My guess is that they're Potentially dangerous, but that's a pretty wild guess.
Alternanthera spp. (A. dentata 'Purple Knight') These weren't on any lists either. They have kind of a Safe vibe to them, but I don't actually know.

Ardisia elliptica.

Ardisia crenata (coral berry) There's very little information out there about Ardisia spp., and what there is is conflicting. The fruits, according to some sources, are definitely toxic, but in the wild they're distributed by birds, which has been one of the main reasons for the Ardisias becoming invasive in Hawaii and Florida and so forth. So they're not universally toxic, obviously. And nobody mentions the foliage at all. So I don't know. I would guess probably Potentially dangerous, on the grounds that the plant is at least known to be able to create toxins, whether they're restricted to the seeds or not.
Ardisia elliptica (shoebutton tree) As for Ardisia crenata, q.v.
Aspidistra lurida, A. elatior (cast-iron plant) These are on several lists, but the lists don't agree when it comes to Aspidistra. I guess Potentially dangerous.
Asplenium nidus, A. antiquum (birdsnest fern, Japanese birdsnest fern) Again, nothing on the lists; I'll guess Potentially dangerous just because that's what I guessed for Adiantum.
Asplundia 'Jungle Drum' Way too new to be on any of the lists. I'd guess Safe, if I had to guess, but that's based on very little.
Cereus peruvianus Cacti are more or less completely missing from houseplant toxicity lists. I suppose the spines make them hard to eat anyway, whether they're toxic or not. So we'll say it probably belongs in the Unpleasant list, as would most cacti. That said, there are a few genuinely toxic cacti out there, and I can't promise that C. peruvianus isn't one of them.
Ceropegia woodii (rosary vine, string of hearts) No information whatsoever, or at least nothing I could track down in time for the post. I would guess Unpleasant.

Chlorophytum comosum.

Chlorophytum comosum (spider plant, airplane plant, mala madre) Chlorophytums are generally considered safe by pretty much everybody, but a couple sources said that they were toxic to cats. This is believable, because they're in the Liliaceae, and there are quite a few things in the lily family which are specifically toxic to cats. However, it's also not believable, because the husband had a cat when I met him, and also a lot of spider plants, and she used to eat the spider plants all the damn time. And, I mean, yeah, she also threw up afterwards, all the damn time, but I always kind of thought that the throwing up was the point. At the very least there's a big difference between a vomiting cat and a dead cat. So I have no idea. I would still favor my actual experience and go with Safe, but I'm conflicted enough that the Chlorophytums wound up on the unknown list, pending more information about how they get on with cats.
Chlorophytum x 'Fire Flash' (Fire Flash, mandarin plant, green orange) As for Chlorophytum comosum, q.v.
Cyrtomium falcatum Some reputable-seeming sites list this as safe for reptile and amphiobian enclosures, but aside from that, no lists include them. If you held a gun to my head I'd go with Potentially dangerous. But please don't. Hold guns to my head.
Davallia spp. As for Cyrtomium falcatum.
Dionaea muscipula (venus flytrap) Another one with the toxicity equivalent of an unlisted phone number. My guess would be Safe.
Echeveria spp. I have no idea; to be on the safe side, I'd say Potentially dangerous, along with Kalanchoe and Tylecodon and all those other guys.
Eucharis grandiflora (amazon lily) Also not on the lists. It is also in the lily family, and grows from a bulb of sorts, two characteristics which tend to go along with being poisonous, so I'd think Potentially dangerous at least, and very probably Dangerous to cats.

Exacum affine.

Exacum affine (persian violet) Only on a few lists. Probably Safe.
Fatshedera lizei (tree ivy) Only rarely included on lists. Based on some of its relatives (Hedera helix, H. canariensis, Schefflera actinophylla and S. arboricola: Hedera helix is actually one of its parents.), I would guess at least Potentially dangerous.
Fatsia japonica As for Fatshedera lizei, except that the few lists that do mention it tend to consider it non-toxic, so I'm all conflicted.
Fenestraria rhopalophylla Basically an unknown plant, so of course it's not on the lists. Going with the general rule that any succulent you don't know anything about should be treated as, minimally, Potentially dangerous, I guess that's what I'll guess here too.

Gasteria 'pseudonigricans.'

Gasteria spp. I didn't come across any lists that mentioned Gasteria spp. separately. They're closely related to Aloe spp., which are toxic, as well as Haworthia spp., which are non-toxic, and I don't know which is the closer relation. My guess, if I were forced to guess, would be that they're probably Safe, though some species have sharp leaf tips which could theoretically be a problem, so they could be as bad as Unpleasant or Potentially dangerous.
Hatiora salicornioides (drunkard's dream) Again, most indications were that cacti are generally Safe except for the spines. This plant doesn't even really have spines, so it's probably either Safe or Unpleasant.
Hemigraphis exotica (waffle plant) Kinda too new for anybody to know much about them. I'd guess Unpleasant.
Hylocereus undatus (dragon fruit cactus) As for Hatiora salicornioides.
Murraya paniculata (mock orange, orange jasmine) Not on any lists; probably Safe in smallish amounts for humans, birds, reptiles and amphibians, considering the uses to which it's been put, historically speaking. On the other hand, it may, like the Citrus spp. to which it is related, cause vomiting and diarrhea in cats and dogs. I don't know whether the small reddish fruits are likely to be safe or not. Wouldn't risk it.
Ophiopogon spp. (lilyturf, Liriope) Not mentioned by anybody, and -- despite what strikes me as perfect suitability for indoor culture, almost never grown indoors. I expect Potentially dangerous, because it's in the Liliaceae, and most of the Liliaceae appear at the very least to be toxic to cats.
Platycerium bifurcatum and other Platycerium spp. (staghorn fern) This one I didn't think of adding to the list until late, so I haven't really looked for it on-line. Neither Toxicity nor Handbook mention it, though, and if there's a general rule for ferns, I haven't been able to find it so far. My guess would be Unpleasant, but that's based on practically nothing at all.
Podocarpus macrophyllus (buddhist pine) Not mentioned by Toxicity or Handbook; the web consensus appears to be that they're of little toxicological consequence, and only the fruits are toxic, causing nausea and vomiting if eaten, but I did run into one site that said that the entire plant was dangerous to pets and children, and that all parts of the plant except for the berry (the seed is toxic, but the flesh around the seed is not) are poisonous enough to kill a large animal. My suspicion is that the low-toxicity people are correct: there are at least a lot more of them. But all I know for certain is that you shouldn't eat the seeds. My guess is Unpleasant.

Radermachera sinica.

Radermachera sinica I guess it's still new enough that it hasn't made it to the lists yet, and there are no relatives I'm aware of. I find myself unable to even make a guess.
Selaginella spp. (spikemoss, resurrection plant, rainbow fern) Not included on any lists, though sometimes recommended for moist terraria. I suspect these are probably Safe, but am uncertain.

So except for a couple minor bits of housekeeping (a promised long post about poinsettia toxicity, which I will post tomorrow, and an index post, which will go up on the 26th), that's the Much-Anticipated and Necessarily Incomplete PATSP Survey of Indoor Plant Toxicity. Which should either be abbreviated MANIPSIPT or MANIPATSPSIPT, both of which look like something Bill the Cat would say. So maybe we'll just call it "The Toxicity List."

If you've:

1) been holding back a disagreement about the placement of a particular species, or
2) you want to tell me something about a plant from the above Unknown list, or
3) you think that even though you don't know whether it's toxic or not, I left off some personal favorite plant of yours and you want to see it go into the mix somewhere, or at least get investigated a little, now would be the time to speak up.

Tomorrow: I wade hip-deep into the ever-burning controversy about whether poinsettias are really toxic or not. Personal scores to settle! Animal testing! Alarmism! It promises to be a real page-scroller. Stay tuned.


9 comments:

Water Roots said...

Great stuff! I loved this series. Can't wait for tomorrow's post. Thanks for sharing all this wonderful information. I really appreciate all the work you put into it.

Anonymous said...

Thank you very much for these posts. I had been wondering about Chlorophytum x 'Fire Flash' since I read on GW that it is poisonous. I couldn't find a reference to prove that anywhere. Thank you for explaining the real danger.

our friend Ben said...

Yet another great post, Mr. S.! I've seen spider plants specifically recommended as great plants to grow for cats too many times to think they're harmful. (And I'll admit, I thought that ASPCA list was a little bizarre as well, to say the least.) I really appreciate your posting this right now, since Nina has pushed me over the edge and I'm finally going to get anoles for the greenhouse this year (after threatening to do so for ages) and of course plan to give them a planted terrarium as home base. Thanks!

Anonymous said...

Since this is the roundup, I'd just like to comment on the relationship of plants, taste and toxicity. Much of my experience is with wild mushrooms (as a teacher, not consumer) and in no way can anyone depend on a good taste as equating with safety. Many people have died painful deaths after depending on "it tasted ok", or "I saw a rabbit eating it". It makes me pretty dubious of trusting even any vascular plant without a record of safe use. That does seem to leave out most houseplants - but kids, dogs and cats hardly ever ask (why do the kids put beans in their ears?). Thanks for red-flagging some of these; it's especially valuable since poison control centers aren't always in focus on all of them.

James said...

As for Radermachera sinica, I know my cat has eaten it a few times, and it makes him throw up, but he's still alive. So it might go on the (huge) 'may cause cats to vomit' list.

Karen715 said...

I've had one cat chow down on a plain green Chlorophytum (Spider plant) over the course of a few days, and not vomit afterward, nor did she seem otherwise adversely affected, so there's a small data point for you.

I don't know specifically about Murraya paniculata, but the leaves of another member of the genus, Murraya koenigii, (Curry Leaf) are used in Indian cooking.

lancetx said...

I have also had a cat who ate a lot of Chlorophytums - and my experience is whenever they eat anything green the point is to throw up, so that's really not an indicator of toxicity. None have ever seemed harmed by them.

Sixwing said...

Thanks for a great series on poisonous plants! I've pointed a coworker who has both plants and cats to these posts - we're forever getting curious about which ones are poisonous, and how much, and you resolved a lot of that.

Anonymous said...

Chlorophytum comosum - Mum grows several plants deliberately for her cat to eat when she's indoors (outdoors, the cat likes Briza maxima), and we gave some plantlets to my boyfriend's mum for her cats. They eat them so enthusiastically she has to rotate them: one out, and the rest growing on in a room her (indoor) boys can't get into. All the cats are pushing ten now, and are only ever sick for obvious reasons (eg eating a whole bowlful of dried kibble then having a big drink of water; stealing spoiled fish from a neighbour's bin). Friends do this too, especially with indoor or city-centre cats that don't have access to vegetated gardens, but I don't know the cats well enough to vouch for their health.