A stand of poison hemlock in Rancho San Antonio, early June.
By Jill Escher
I am no expert on botany but is it my imagination or am I seeing a huge abundance of poison hemlock plants here in Northern Calif this year? Normally such sightings might be a mere curiosity, but for me, the mother of two children with autism who are known to chew and ingest any number or sticks, plants and leaves within grabbing distance, this seems like a major threat. Why? Hemlock is so toxic that even a small dose can be fatal.
I am no expert on botany but is it my imagination or am I seeing a huge abundance of poison hemlock plants here in Northern Calif this year? Normally such sightings might be a mere curiosity, but for me, the mother of two children with autism who are known to chew and ingest any number or sticks, plants and leaves within grabbing distance, this seems like a major threat. Why? Hemlock is so toxic that even a small dose can be fatal.
My son loves hiking, and we're seeing hemlock everywhere. As much as we might not like it, a lot of kids and adults with more severe forms of autism (mine are both nonverbal and severe) compulsively chew on or ingest inedible objects, including plants. For many of them, interventions, including behavior modification, fail to reduce the incidents. So when you take kids or adults of that persuasion on a hike, as I often do, some degree of plant grabbing-chewing-eating is fairly inevitable.
In my experience, this is almost always harmless. But now, enter poison hemlock, which blooms in the summer months.
The past winter and spring brought heavy rains. This, according to the Master Gardeners of Santa Clara County, has generated growth of all sorts of plants, including the hemlock. So no wonder I've seen stands of it nearly everywhere we hike and adventure, for example, in Rancho San Antonio, Alum Rock Park, Half Moon Bay Coastal Trail, and most recently, Seabright Beach in Santa Cruz. In fact, my daughter and I were exiting the beach when she grabbed at the plant and before I could even say "Stop!" or "Oh my frickin' gawd!" a piece of stalk was in her mouth. I quickly nabbed it and rinsed her mouth, and all was well. But, I thought, what if I was one of those autism parents who did not know about the dangers of hemlock? Well, my daughter might easily be dead, or on a ventilator.
Which is the reason for me writing this blog. Autism parents must learn how to spot this plant. This is a life or death matter. I know, what autism parent wants to ascend the learning curve of yet another topic, or impose on themselves yet another worry? But you must: just a few leaves, or other parts, of the hemlock plant can kill—a small dose can cause respiratory collapse. And according to news reports, hemlock is abounding all over the country, not just here in Northern California. If you spend time outdoors, as we do, please take just three minutes to familiarize yourself with this nasty plant.
In my experience, this is almost always harmless. But now, enter poison hemlock, which blooms in the summer months.
The past winter and spring brought heavy rains. This, according to the Master Gardeners of Santa Clara County, has generated growth of all sorts of plants, including the hemlock. So no wonder I've seen stands of it nearly everywhere we hike and adventure, for example, in Rancho San Antonio, Alum Rock Park, Half Moon Bay Coastal Trail, and most recently, Seabright Beach in Santa Cruz. In fact, my daughter and I were exiting the beach when she grabbed at the plant and before I could even say "Stop!" or "Oh my frickin' gawd!" a piece of stalk was in her mouth. I quickly nabbed it and rinsed her mouth, and all was well. But, I thought, what if I was one of those autism parents who did not know about the dangers of hemlock? Well, my daughter might easily be dead, or on a ventilator.
Which is the reason for me writing this blog. Autism parents must learn how to spot this plant. This is a life or death matter. I know, what autism parent wants to ascend the learning curve of yet another topic, or impose on themselves yet another worry? But you must: just a few leaves, or other parts, of the hemlock plant can kill—a small dose can cause respiratory collapse. And according to news reports, hemlock is abounding all over the country, not just here in Northern California. If you spend time outdoors, as we do, please take just three minutes to familiarize yourself with this nasty plant.
There are two types of hemlock relevant for our purposes: poison hemlock (Conium maculatum) and water hemlock (Cicuta douglasii). These two are different plants, with different features, and that cause different types of poisoning. Though water hemlock is the more acutely poisonous, I discuss poison hemlock here because that's the species I've been seeing out on the trails.
Spotting Poison Hemlock
Where it's found: Along trails, creeks, creekbeds, roadsides, and irrigation ditches. On edges of cultivated fields and in waste areas.
It flowers in June-July, when it is most toxic. But the dry plants retain toxins for a few years.
At left, the clump of poison hemlock growing by the Santa Cruz Harbor, at the entrance to Seabright Beach, in mid-June.
It flowers in June-July, when it is most toxic. But the dry plants retain toxins for a few years.
At left, the clump of poison hemlock growing by the Santa Cruz Harbor, at the entrance to Seabright Beach, in mid-June.
Flowers: The flowers are small, white, clustered in umbels up to 4–6 inches across. An umbel is a group of short flower stalks which spread from a common point, somewhat like umbrella ribs.
This is the flower and seeds when dried up. Still poisonous in this state, though apparently less so.
Leaves: The leaves have an arrowhead configuration. They are fern-like, toothed, finely divided and have a strong odor when crushed.
Stalks: The plant typically grows about 6-8 feet tall, it is notable for its smooth and not-hairy stalk. The stalk, which is hollow, is often purplish at the base, with some purple spots further up the stalk. However, I have seem some plants with a minimum of purple blush at the base and very few splotches up the stalk, so beware.
I've found videos more helpful than static websites at helping me identify the plant, here are a few:
• Someone called The Nature Dude: https://www.youtube.com/watch?v=NJ0pqziTb1Q
• Short video comparing poison hemlock and water hemlock: https://www.youtube.com/watch?v=22TUOjdGKII
• From Oklahoma, but still the same plant: https://www.youtube.com/watch?v=NyGMhtdbLQI
• About hemlock infestation on the Truckee River: http://www.kolotv.com/content/news/Poison-Hemlock-found-near-Truckee-River-423728634.html
Again, big disclaimer— I am just a mom and not a botanist, or even a gardener. I encourage you to do your research until you become comfortable identifying this potent bit of our local flora. Thanks for your attention, I have the deepest sympathy for all my fellow autism families where kids compulsively chew or eat plants, and I wish you happy and safe hiking and exploring.
• Someone called The Nature Dude: https://www.youtube.com/watch?v=NJ0pqziTb1Q
• Short video comparing poison hemlock and water hemlock: https://www.youtube.com/watch?v=22TUOjdGKII
• From Oklahoma, but still the same plant: https://www.youtube.com/watch?v=NyGMhtdbLQI
• About hemlock infestation on the Truckee River: http://www.kolotv.com/content/news/Poison-Hemlock-found-near-Truckee-River-423728634.html
Again, big disclaimer— I am just a mom and not a botanist, or even a gardener. I encourage you to do your research until you become comfortable identifying this potent bit of our local flora. Thanks for your attention, I have the deepest sympathy for all my fellow autism families where kids compulsively chew or eat plants, and I wish you happy and safe hiking and exploring.
Jill Escher is president of Autism Society San Francisco Bay Area. She frequently goes hiking with her son and daughter who have nonverbal autism.
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