Death camas

As a mystery writer, I spend a lot of time thinking about how to kill people. But I like my murder to take place offstage, without a lot of blood. So I also spend a lot of time thinking about poisons.

I also like to garden.

Aside from the naturally occurring mutual benefits that reveal themselves upon combining the two activities—murder (Where to stash the body?) and gardening (Where to find moderately priced compost?)—the flora and fauna of the environment enclosed by my backyard fence fuel the writer’s imagination.

Thus I bring to you the first post in a new series: The Backyard Poisoner (How To Get the Most out of Your Garden).

Born in the Pacific Northwest, I was raised on cautionary tales about wildlife. I know several foolproof methods for escaping a rampaging bear, most of which are in conflict with each other. It is difficult, for example, to play dead while climbing a tree, and nearly impossible to do both while running uphill very fast. Throwing rocks is always a reasonable option—which explains why most British Columbians can’t walk past a body of open water without chucking a rock into it: practice makes perfect when it comes to bears.

As a rugged British Columbian, I am confident in my ability to distract cougars, bobcats, wolves, coyotes and raptors of all sizes; I always enter the woods armed with a small creature for just this reason—whether that small creature is a small pet or a small child. (This is also why, incidentally, most British Columbians have at least one friend who is smaller than themselves.)

But it didn’t occur to me until I began writing mystery fiction what a very dangerous place British Columbia can be. A remarkable number of native plants can kill, and many of them grow everywhere. I pass at least a dozen lethal plants just walking to work. And the deadliest animals are not in the woods; they’re in my backyard, next to my woodpile.

When it comes to death by poison, my small children are no help: I am more likely to poison myself picking a bouquet for the dinner table than I am to encounter a cougar on any day of the week.

Really, I’m not sure why I had kids in the first place.

The best poisons get the job done swiftly and leave little trace, mimicking a natural event or leaving behind a natural byproduct. A well-tempered murder by poison can be purposefully misattributed to the foolhardiness of the victim: Poor amateur forager Joe, who wasn’t sufficiently educated about the differences between Amanita phalloides and Amanita citrina and whose demise can be chalked up to the mushroom soup he ate for lunch. (Never mind that no one of sound mind sets out to forage for Amanita citrina because it tastes like cardboard tossed lightly with dirt; Joe’s questionable culinary choices, too, can be attributed to the amateur nature of his foraging activities—all proving that attendance at a single two-hour lecture by a guest mycologist at the Galiano Island Mushroom Club does not a successful forager make.)

But not many of us grow mushrooms in our backyard; getting the most out of our garden means considering more commonly grown native and non-native species.

The Lekwungen-speaking peoples of the Coast Salish on Vancouver Island have cultivated kwetlal (camas in English and Camassia quamash in Latin) as a food source for millennia.1, 2 The plant spends the vast majority of its annual cycle unremarkable to the human eye, its sword-like medium-green fronds blending in with other low-lying open-woodland ground covers. It likes sunlight and drier weather and can be found in open meadows or in seasonal wetlands that dry out as soon as the spring rains taper off, on the hillsides outside of Victoria and Sooke, or on the rocky slopes of the nearby Gulf Islands. It especially likes the soil beneath Garry oak trees (Quercus garryana), unique to this coast.

In mid-spring, this normally unremarkable plant suddenly blooms, carpeting the ground with a purple-blue so intense that it makes all the other colours of a British Columbia spring seem sickly by comparison. When we walk through a camas meadow in May, I feel like Dorothy must have felt when she touched down in Oz—a field of technicolour at our knees and a chorus of excited bees so loud that conversation stops until we’ve crossed the meadow and are back beneath the relative arching silence of fir and arbutus.

The camas plant’s tubers must be boiled, roasted or steamed for several hours—and once properly cooked are slightly sweet, reminiscent of a parsnip or baked pear in both texture and taste. Well-cooked camas, or kwetlal, was (and for some still is) a staple of the Coast Salish diet; under-cooked camas is not very digestible—it contains inulin, which causes an individual’s digestive tract to revolt, producing enormous amounts of gas: an unpleasant experience, but not a successful poisoning.

The only reason camas plays a role in this discourse on poison is because it looks very much like a deadly poisonous plant, one that grows in exactly the same ecosystem.3 Biologically, camas and death camas (yes, that’s really its name) aren’t closely related. But aside from taste-testing them, unless you are very well versed in their minor visual differences, the only foolproof way to differentiate between the two plants is to wait for mid-spring: camas blooms irridescent blue; death camas is funereal white.

In all other aspects, the plants are easy to confuse. The leaves are very similar. The tubers are alike, particularly if they’re small—and, in fact, look very like the tubers of another edible plant, the wild onion. All parts of the death camas (Toxicoscordion venenosum or Zigadenus venenosus, depending on the scientific authority you subscribe to) are toxic; touching the plant with a bare hand can lead to unintended consequences if the same hand is next used to eat lunch.

The kwetlal fields maintained and harvested by the Coast Salish peoples were often tended by the women in the community. Historically, great care was taken to remove the white-flowering plants from the cultivated plots during bloom time each spring.

Today, the most common fatal encounters are by livestock. The only animal not affected by zygacine, the deadly toxin in death camas, is the death camas miner bee, which collects the poisonous pollen for its larvae. There’s even scientific evidence to suggest that the pollination of the death camas plant is largely dependent on the activities of the wee bee.4

Death camas miner bee (Andrena astragali) in action

Gardener’s notes:

Death camas is a lovely addition to the backyard poisoner’s garden, particularly planted en masse with camas, providing a stunning mid-spring show and an important food source for the native pollinator Andrena astragali (death camas miner bee).

First responder’s notes:

Victim experiences nausea, vomiting, abdominal pain, dizziness, faintness—and in extreme cases, low blood pressure, slowed heart rate, and ataxia. Death is possible without aggressive treatment of the victim’s more dangerous symptoms.5

Writer’s notes:

Murder by death camas has advantages and disadvantages.

Pro:

It’s not difficult to convince someone to eat death camas: it looks like wild onion and would go well in a stew. Symptoms of zygacine poisoning mimic symptoms of certain types of food poisoning and might initially be dismissed by the victim. Medical practitioners may not immediately recognize symptoms of death camas poisoning; this works to the killer’s benefit, as death by death camas can take time.

Contra:

Poisoning by death camas is messy and not particularly quick—all that vomit, for at least several hours. Large amounts of death camas must be ingested for the results to be fatal—at least four or five bulbs if the individual is relatively small, more if the person is bigger. There’s no antidote to zygacine poisoning per se, but prompt medical treatment of the symptoms often results in a victim’s full recovery, particularly if the victim wasn’t very hungry and didn’t each much stew.

Pathologist’s notes:

Zygacine may show up in toxicology tests post-mortem, although possibly not in high enough concentrations to result in definitive conclusions—and the pathologist would need to have suspicions, as zygacine is not a toxin typically tested for.

Murderer’s best-case scenario:

A really tasty stew, a very hungry and smallish victim, a significant distance between dinner service and the nearest hospital, and no possibility of unexpected visits by well-meaning neighbours with medical training.

Final score (taking into account toxicity, certainty, detectability, and ease of use, including preparation and clean-up): 5/10

Footnotes:

1 Grescoe, Taras. The Lost Supper: Searching for the Future of Food in the Flavors of the Past. Vancouver, BC: Greystone Books (2023).

2 “Restoring Camas and Culture to Lekwungen and Victoria: An interview with Lekwungen Cheryl Bryce”, Briony Penn for Focus Magazine, 2006.

3 Turner, Nancy J. Common Poisonous Plants and Mushrooms of North America. Portland, Oregon: Timber Press (1991), pp. 106–107.

4 “A rare relationship between death camas and death camas miner bees”, Jeff Mitton for Colorado Arts and Sciences Magazine, 4 January 2022.

5 Turner, Nancy J. “Common Poisonous Plants”.