Poisonous Plants of Coastal British Columbia


I've thumbnailed links to larger pictures. The page with full sized pictures will still take some time to download. If there is sufficient interest I will also link to very high resolution scans of the pictures. Be aware though that these would be jpegs of several megabytes in size - each.


I've been attempting for some time to learn more about all of the plants of this locality , with a view to providing photographs to aid in identification and listing uses of plants and their parts. It soon became apparent to me that I didn't know much about the toxic plants: I'd never bothered to learn about them since they are by definition not edible, and they do not provide material for use such as cordage. I knew a little about false hellebore because it is so readily identifiable, but I couldn't remember where I'd seen it, in our valley. I remembered death camas being pointed out to me many years ago - but not with a definite identification. Last but not least there is water hemlock: I had no idea about this one. Since I'm interested in edible plants and there is always the warning about confusing cow parsnip with this stuff - I decided to learn about it first.


Water Hemlock - cicuta sp

This is usually described as being the most violently toxic plant in the Northern Hemisphere. Descriptions of the amount of the stuff it takes to kill you and the team of horses you rode in on - vary. The general conscensus seems to be that a piece of root the size of your small finger is definitely the end of the line for one person. Since the root is divided into numerous tuberous branches of that size, one plant would do the job on you and your team. Apparently this isn't the plant used on Socrates (that was conium or poison hemlock), so anyone considering a quiet end shouldn't consider it. The symptoms of poisoning are fast onset of convulsions, often with bitten off tongue... You soon get the idea of it being nasty stuff. The onset of symptoms often comes within 15 minutes so you may be out of luck getting to treatment if you are in the bush. Treatment with barbiturates and anti-convulsants have been successful if applied in time. As I will stress below, and this cannot be stressed enough, the plant looks innocent, smells absolutely delicious, and the toxic components (cicutol and cicutoxin) are concentrated in the yellow orange sap. You better be careful to clean your hands and knife properly if sectioning the root! Even given my limited experience with this plant, it's readily apparent that the toxin levels vary greatly in various parts of the plant and between plants. In the flowering season which is when most people will be able to identify the plant the toxins are mainly concentrated in the roots. In the early growing season the toxins are throughout the whole plant, and at seeding time the toxins are concentrated in tubes around the seeds. One thing to notice is that the plants show no signs of insect damage at all. You will see that bees are not poisoned by the pollen (of course) so there will be insects around the plants. There have been surprisingly few tests of toxicity on animals but enough to show that no part of the plant should be trusted to be non-toxic even when dried.

I tried to remember if I had ever seen the plant, and came up blank. The next step was to go out armed with descriptions and a good pair of binoculars (at flowering time) to hunt the swamps. I was relieved to find not one single plant in any of the places I frequent so I wasn't wrong in thinking that I hadn't seen it before. I then decided to try some spots that I don't often go to and found it at once.

Actually finding Water Hemlock:

The trick is that this plant flowers just as the cow parsnip is losing its flowers and beginning to seed - at least around here. So you go cruising with a pair of binoculars. Distribution is very localized around here. Once you've found what looks like the pictures on this page, dig up some roots with a digging stick (just a pole sharpened to a flattened point) so that you minimize breakage of the roots and poisoning of water. The chambered roots are definitive. The usual description of water hemlock is that its a plant with an umbrella shaped mass of white and green flowers. While around here it flowers when the cow parsnip is turning to seed, there are lots of other umbelliferae that will be flowering and will appear similar. When the cow parsnip is flowering you just won't notice the water hemlock unless you have a lot of experience in what to look for - and at this time the stems of the water hemlock are poisonous. All in all, once you have found some water hemlock, it's worth taking a few hours to closely study both the plant and its surroundings. It's studying the key features singly that lead to trouble:

What appear to be aphids on the stems on the second picture - aren't. Just little bumps on the stems.

  1. Supposedly this plant is found in or very close to water. Naturally I found my first specimens on a dry sandy bank. What I have seen in every case so far though, is that standing water will be nearby - 5 metres (fifteen feet) at most. If you find what appears to be hemlock look close by for water. Following the progress of the plants I've seen that where they occur may appear dry, but will be subject to flooding in times of heavy rain. The plants I've followed have been surprisingly drought resistant for plants that normally grow in water. They showd no stress after several weeks in dry conditions.
  2. Often water hemlock is supposed to have a purple tinged stem - naturally my specimens didn't. I have found such specimens where the identification is difficult, but on the group of plants I studied with definite identification - none changed from green stems over the growing season with the exception of a purple tinge where the stem meets the roots. This is not obvious until you dig up the roots.
  3. The most definitive identification given in many books is that the veins in the leaves end at the notches on the serrated leaves. Well all the pictures of leaves came from specimens with the most definite feature - chambered roots. With magnification this is apparent but it can be hard to see this without magnification. The leaf pictures are all of cicuta douglasii.

    The first two are the same leaf viewed from underneath with slightly differing lighting - top lit 10X magnification. The veins are definitely going to the notches - but remember this is with good lighting and magnification.

    When you view the leaf from the top with some added dirt, it becomes hader to tell - even with good lighting and at 10X! The same leaf is shown with bottom lighting at 10X in the second picture.

  4. The most positive ID comes from digging up the rootstock and sectioning it. If the part where the stem is joined to the root has horizontal chambers then you definitely have water hemlock of some kind. While you are busy doing this, I think that I can assure you that you'll remember all the stuff about the roots being the most toxic part of the plant. Very little information is available on what happens if you manage to cut yourself with a knife with cicutoxin on it - but it might be as well to know that the Okanagan used this stuff as an effective arrow poison. While the only remaining record is that the poison acted as a coagulant, I didn't see this as being evident through one small test. My belief is that the poison acts very quickly on the nervous system when it is introduced into the bloodstream. Precautions follow but be aware that the chambering varies from very obvious on large plants to much less obvious on some smaller ones - so don't become careless. You'll always find it once you know where to look. In the picture below notice purple tinge on stem base, light brown roots divided into "fingers" and yellow orange sap oozing on fresh cut. All smaller roots have chambering too where they join the main root. At seeding time, the smaller roots atrophy and the main central root thickens so the whole appearance changes!

    Root sections taken at seeding time. The first two pictures show a root section taken close to the surface. In the first the secton is top lit and the chambers are hard to see - the same section is then shown bottom lit to make the chambers more evident.

    Make sure that you cut the root down the middle to see the chambers clearly! These pictures show a root at 10X magnification - taken late in season at seeding time. Note the two large lower chambers and the narrower chambers which are found vertically above them on the root.

  5. Once you cut the root, it exudes a yellow orange resinous looking sap. That's what contains the poison. It has a sweet smell of celery, carrots, parsnip - or a combination, depending on the individual plant you cut up and when it is cut. Supposedly it tastes sweet but I do wonder about whether the person crazy enough to try it had heard of the effects.. The bad news is that some plants exude very little of this stuff, others pour it out. I would suspect that some individual plants are vastly more toxic than others.

    You'll have noticed in the pictures above that little sap is evident. The root was dug at seeding time, and other samples showed the same. Previously in the flowering season roots had exuded sap to the extent that the whole section would look orange and blurred. The section below shows the total sap that bled out after 20 minutes.

Precautions - Again:

I have seen incredible variation in individual plants, and the key features may not be apparent or may be confusing. The only real key to identification is sectioning the roots which exposes you to danger. Wearing rubber gloves or just using plastic bags over the hands is a good precaution as is thoroughly cleaning the knife.

The only effective means of eradicating the plant is to grub it up and burn it prior to seeding -as apparently some of the roots can survive over a winter. I don't normally kill things just because they are dangerous but this plant is reported as attractive to livestock and children - and should not be allowed in places they frequent. I'd have to agree that the roots smell delicious. For much grubbing of roots an iron bar is better than a digging stick since the roots tend to follow hollows between rocks. You'll still break open enough roots to poison nearby water, killing fish, invertebrates, and anything that drinks the stuff. I'm not sure how long the water stays poisonous - and I've been unable to find information on this.


Conclusions:

About the only way that you are going to learn about this plant is to go out at flowering time and dig up some to section the roots. I've only shown one type of cicuta and there are others which will look different. I'm glad that I spent time learning about this plant as it is common in some areas and could be a real problem if you gather some of it by accident.




Jimbo

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