If you spend time outdoors in Colorado, knowing about poisonous plants is a must. This guide covers the poisonous plants in Colorado – deadly and widespread species you need to identify.
Many of these plants are common and can cause serious harm. We’ll help you recognize them and know what to do if you have contact.
Poisonous Plants In Colorado – Deadly And Widespread
Colorado’s diverse landscapes are home to several highly toxic plants. Some are dangerous to touch, while others are fatal if ingested. Let’s look at the most critical ones.
Water Hemlock (Cicuta douglasii)
This is often considered North America’s most toxic plant. It grows in wet areas like stream banks and ditches.
- Looks like: A tall plant (up to 6 feet) with clusters of small white flowers (umbels). The stems are hairless and have distinctive purple streaks or splotches.
- Deadly part: All parts, especially the roots. The root may smell like parsnip or celery but contains a violent nerve poison.
- Effect: Ingestion causes violent seizures, stomach cramps, and can be fatal within hours.
Monkshood (Aconitum columbianum)
Also called Wolfsbane, this beautiful but deadly flower thrives in mountain meadows and along streams.
- Looks like: Tall stalks with helmet-shaped blue, purple, or white flowers. The leaves are deeply lobed.
- Deadly part: All parts, especially the roots and seeds. Toxins can even be absorbed through the skin.
- Effect: Ingestion leads to numbness, vomiting, heart and lung paralysis. Handling it without gloves can cause tingling.
Death Camas (Toxicoscordion venenosum)
This plant is a major risk because it looks like edible camas or wild onions. It grows in grasslands and foothills.
- Looks like: A grass-like plant with a cluster of cream-colored flowers at the top. It grows from a bulb that looks like an onion but does not smell like one.
- Deadly part: All parts, especially the bulb.
- Effect: Ingestion causes vomiting, weakness, slow heart rate, and can be fatal.
Poison Hemlock (Conium maculatum)
This invasive plant is common along roadsides and disturbed areas. It’s the plant that killed Socrates.
- Looks like: A tall plant (3-7 feet) with lacy leaves and small white flower clusters. The stem is hairless with prominent purple spots.
- Deadly part: All parts. It contains neurotoxins that disrupt the nervous system.
- Effect: Ingestion causes trembling, salivation, dilated pupils, and potentially death from respiratory failure.
Oleander (Nerium oleander)
While not native, oleander is a popular landscaping shrub that is extremely toxic. It’s often planted in urban areas.
- Looks like: A shrub with long, dark green leaves and showy white, pink, or red flowers.
- Deadly part: Every single part—leaves, stems, flowers, sap, and even the water in a vase containing cuttings.
- Effect: Ingestion affects the heart, causing irregular rhythm, nausea, and can be fatal. Never burn it, as the smoke is also toxic.
What To Do If You Touch or Ingest a Poisonous Plant
Acting quickly is crucial. Here are the steps you should follow.
For Skin Contact (like Poison Ivy or handling Monkshood):
- Immediately rinse the skin with lukewarm water and soap. Don’t scrub hard.
- Wash under your fingernails and any clothing that may have sap on it.
- Use calamine lotion or hydrocortisone cream for itching later.
- See a doctor if you have a severe reaction or rash on your face or genitals.
For Suspected Ingestion:
- Call the Poison Control Center immediately at 1-800-222-1222. Do not wait for symptoms.
- Do not induce vomiting unless a medical professional tells you to.
- If possible, identify the plant. Take a photo or bring a sample with you.
- Go to the nearest emergency room or call 911 if the person collapses, has seizures, or trouble breathing.
How to Safely Remove Poisonous Plants From Your Yard
Removing these plants requires caution. Always where long sleeves, long pants, and sturdy gloves.
For Non-Invasive Toxic Plants (like a single Monkshood):
- Dig out the entire plant, including all of the root system.
- Place it directly into a heavy-duty garbage bag. Do not compost it.
- Clean your tools and gloves thoroughly after.
For Invasive Patches (like Poison Hemlock):
- For large areas, consider using an herbicide labeled for broadleaf plants, applied carefully.
- Mowing is not recommended right before flowering, as it can spread seeds.
- Dispose of all plant material in sealed trash bags, not yard waste.
Remember, its often best to hire a professional for widespread or dangerous infestations. They have the right protective gear and experience.
Common Look-Alikes: Dangerous Confusions
Many poisonous plants resemble edible ones. Here’s how to tell the difference.
Wild Onion vs. Death Camas
This is the most dangerous mix-up. Wild Onions have a distinct, pungent onion or garlic smell when the leaves or bulb are crushed. Death Camas has no onion smell at all. If it doesn’t smell like an onion, don’t touch it.
Queen Anne’s Lace vs. Poison Hemlock
Queen Anne’s Lace (wild carrot) has a hairy stem, often with a single purple flower in the center of its white bloom cluster, and it smells like carrot. Poison Hemlock has a hairless, purple-spotted stem and smells musty or like mouse urine.
Elderberry vs. Water Hemlock
Elderberry is a woody shrub or small tree with a brown stem with bumps. Water Hemlock is a herbaceous plant with a smooth, purple-streaked, hollow stem. Never forage near water without positive ID.
Protecting Children and Pets
Kids and pets are especially vulnerable. Teach children never to put any part of a plant in their mouth. Supervise them closely in areas with unknown vegetation.
- For pets: Know the plants in your yard and on your walking routes. Train dogs to “leave it.”
- Watch for symptoms like drooling, vomiting, diarrhea, lethargy, or tremors in pets.
- Keep the number for the ASPCA Animal Poison Control (888-426-4435) handy.
FAQ: Poisonous Plants in Colorado
What is the most deadly plant in Colorado?
Water Hemlock is generally considered the most acutely toxic. A piece of root the size of a walnut can kill a cow.
Is poison ivy found in Colorado?
Yes, poison ivy is present in some parts of Colorado, especially near waterways. It’s less widespread than in eastern states but still exists. Remember “Leaves of three, let it be.”
Are there any poisonous berries in Colorado?
Yes. Baneberry has shiny white or red berries on a red stalk. Lily of the Valley (planted in gardens) has red berries. Both are toxic. Never eat wild berries unless you are 100% certain of their identity.
Can you get a rash from touching poison hemlock?
Yes, the sap can cause skin irritation and dermatitis in some people, similar to a poison ivy rash. Always wear gloves when handling it.
What should I do if my dog eats a poisonous plant?
Contact your vet or the ASPCA Animal Poison Control Center immediately. Try to identify the plant to give them accurate information. Time is critical for treatment.
Final Tips for Safety
Respect is the key to coexisting with Colorado’s flora. Learn to identify the few dangerous species in your area. When in doubt, don’t touch, and definitely don’t taste.
- Carry a field guide or use a reliable plant ID app on hikes.
- Stick to established trails to minimize contact.
- Educate everyone in your household about the risks.
By knowing what to look for, you can enjoy Colorado’s incredible natural beauty safely and with peace of mind. A little knowledge goes a long way in preventing a serious accident.