The Poisonous Plants of Puerto Rico

Carrasco in Foreground

It takes thousands of years for a rainforest to grow a proper canopy. A canopy with leaves so thick, not a single ray of light can penetrate to the forest floor. There is very little bushwacking when walking through primary rainforest, as there is not enough light to support vegetative growth below. 

One mile an hour. That’s how fast a person can travel through primary jungle with a healthy canopy. That may sound slow but it’s actually quite fast. Most hikers would have a hard time traveling at two mph on a maintained trail in Colorado. 

Puerto Rico’s rainforest got annihilated during Hurricane Maria and the leaves from the jungle canopy were ripped away by winds exceeding 150mph. Suddenly, the understory was exposed to sunlight for the first time in possibly hundreds of years. The foliage underneath began to grow in unison, exponentially, each species competing with another, growing taller, faster, taking up every available inch of real estate. Suddenly, walking through the jungle became a very real challenge. You’d better have a machete and you’d better know your plants––because some of them are quite sinister. 

When I first started jungle-bashing (primarily looking for caves) I thought it might be a good idea to see if there was poison ivy in Puerto Rico as I am highly allergic to it. A quick internet search simply produced a ‘No.’ But I wasn’t asking the right questions, you see. I should have asked: What plants in Puerto Rico are worse than poison ivy? Well, I found out the hard way. Here is a list of the worst.

Carrasco (Guao)– This is the worst poisonous plant you will find in Puerto Rico. Its related to poison sumac but its effects are much worse to those who are affected. If you have had reactions to poison ivy or its relatives, beware of this plant! The leaves look like holly– albeit, less festive.

Carrasco. New Growth
Mature Carrasco

The oil on the leaf is powerful and will react to the skin causing large blisters after 2-3 days of exposure. It can resemble a chemical burn and is extremely itchy.

Blisters from Carrasco Exposure

Making this plant especially nasty are the barbs on the leaf, which can pierce through clothing and inject the skin. If exposed to this plant, be sure to wash thoroughly with soap and water. I have been told that applying rubbing alcohol to the affected areas will neutralize the urushiol in the plant’s sap, although this has not seemed to help me.

Carrasco ‘trees’

Extremely hot showers will intensify the itching but provide some relief once the affected areas are scalded. An over-the-counter antihistamine like Benadryl or Claritin can help reduce the reaction. A steroid shot (like Solu-Medrol) is a last resort although extremely effective. Most doctors on the island will have no knowledge of Carrasco. Apparently jungle-bashing isn’t a popular pastime here. Your best defense against this plant are long sleeves and pants, gloves, thick socks or gaiters. I double layer––which is almost unbearable in the heat––but preferable to three weeks of itching.

Chicharrón (Christmas-Bush, Cocks Spur, Poison Ash)


Often confused with Carrasco, Chicharrón is another poisonous plant similar in appearance to Carrasco, although the leaves are smaller, cupped, and often reddish in color.

The word chicharrón is used for a type of Puerto Rican street food of deep fried pork skin which resembles the wound this plant can inflict. It grows well in dry areas and is common in Guanica State Forest.

Treatment is the same as Carrasco.

Stinging Nettles (Ortiga Brava)

This native plant can grow to 15-feet tall but rarely grows higher than 4-feet. Its broad, green leaves are serrated and warty. Yes, warty. Anything with warts should be avoided––let this be a life lesson. The stinging hairs can be observed on the underside of the leaf. Once they are touched, the pain feels like fire-ant bites. The sting is immediate but doesn’t last more then a few hours. Fortunately, this plant is easily identified and avoided––especially after touching it for the first time.

Sawgrass (Twig-sedge)


This isn’t a poisonous plant but it will kick the crap out of anyone who walks through it. I thought it appropriate to add to the list. As the name implies, it looks like grass yet can be 10-feet tall and is common along river banks. Its leaves are serrated and sharp as a razor. As a kid in Florida, my friend and I were playing in sawgrass of the same species and he cut his leg so badly I could see the subcutaneous fat beneath. Stitches were required.

Pica Pica (Cowhage, Oyo de Venado, Devil Bean)

Pica Pica

The Spanish word ‘picar’ or ‘pica’ roughly translates to the word ‘itch’. During the winter months this hearty vine produces seed pods, or beans, which grow a coat of fine, velvet-like hairs. Should you be unfortunate enough to get these hairs on your skin, or are downwind of the plant when it is shedding, the all encompassing ‘itch itch’ will commence. It would be the equivalent of getting fiberglass insulation on your skin. The itching won’t stop until the hairs are removed. This can be down with soap and water. Remember to wash your clothes too.

Hiking Mt. Dundas, Greenland

Paul and I are in Thule, doing some work for GrIT (Greenland Inland Traverse). After work we decided to do the classic climb of Mt Dundas- which is a steep but flat topped mountain just outside of town. Here’s a couple pics.


Picture of Thule taken from the air during the 1960’s, Mt Dundas in background. The trail up the mountain is highlighted in red

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View from the top, looking north over Wolstenholme Fjord


The view of Thule as it is today.


Backpacking Coyote Canyon

Took our nephew Joseph on his first backpacking trip to Coyote- one of the most beautiful canyons in the Escalante region. We planned a four day hike starting at the Dry Fork- near the famous slots of Peek-a-boo and Spooky Gulch.


Peek-a-boo Gulch


Peek-a-boo, Spooky, and Brimstone are tributaries of Coyote Dry Fork. You can drop your pack at the entrance and explore them as a side hike. The entrance to Peek-a-boo is a tricky little 15′ climb. Hand and foot holds have been pecked out of the rock to aid in climbing but they are worn now. We tied a rope around the waist as a simple belay. You can climb out of the gulch where it pinches at the end, no down-climb or rappel necessary.



Upper Peek-a-boo

2    Spooky Gulch. We were told by a local guide that it needs to rain directly above these slots in order for them to flash flood. Still, it was an unnerving thought.

Side note: I always use tennis shoes on my hikes and packrafting trips. They drain water well, are comfortable, and easy to scramble in. The desert has been the one place where I’ve developed blisters due to the sand. This time we tried wearing ziplock bags on our feet then the sock on top. That idea kinda worked. It kept the sand off our feet but didn’t stop the sand from building up in our shoes. We were constantly pulling them off and dumping the sand out. I didn’t develop blisters but I’ve come to the conclusion that the desert may be the one place where I will need to wear traditional hiking boots with gaitors. I will still need the tennis shoes though when hiking in water. Bummer. I’m a lightweight backpacker and hate bringing multiple pairs of footwear. I don’t even bring camp shoes. Anyone have a better way of getting through the desert when encountering sand AND water?

IMG_4921IMG_4952Spooky Gulch

IMG_4939It can be pretty dark down there.

IMG_4996Nice sand dune near the entrance to Brimstone Gulch. Visiting Brimstone slot is a long, sandy hike down Coyote Dry Fork and fewer people put the effort in to see it. Maybe it’s the name- it certainly isn’t as cool as Peek-a-boo or Spooky. But in my opinion, Brimstone is the best of all three.


Megga face plant while running down the dune! Ha! Sand everywhere but he was a good sport!


Backpacks on, headed down Coyote Dry fork. As you can see, the canyon is very narrow at times. There isn’t any water for the first 11 miles and not very many people visit this area. We had to carry a gallon of water each for this section.


Tumbleweed blocks the way. “Careful, could be snakes in there.”


We found evidence that cows like this slot too. These tight spots aren’t as fun with backpack on.


Lowered packs with rope.


Reminds me of a scene from Indiana Jones.


The canyon opens and the walls rise.

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Huge sandstone cave!


Just kidding.


Prickly Pear Cactus in bloom


Looking forward to water!


Nice camp spot. Joseph tried making friction-fire with bow drill he made from wood found along hike. Lots of smoke but no cigar.


About to find water near Sleepy Hollow.



Coyote Canyon proper. Now our tennis shoes and neoprene socks come in handy! You can walk in the water barefoot, which is nice, but the trail always cuts through the brush and there is a couple different species of poison ivy which can be hard to identify. We saw people in shorts and short sleeve shirts- including children. I have made this mistake myself and had to get epinephrine shots to counter the effects of this poisonous plant. Do yourself and your kids a favor and wear pants, long sleeve shirts, and gloves.





Anasazi cliff dwellings


Coyote Natural Bridge




Cliff Arch




The scramble up Crack-in-the-wall. It actually is a crack in the wall- go figure. Backpacks won’t fit through the slot.


A 50′ rope is used to haul the packs up. The sandstone is very abrasive and can wear or cut your rope- have something thicker than string.


The last little climb at the very top. Try to plan your ascent early in the morning or late at night to avoid the blistering heat.


At the top of Crack-in-the-wall. I’ve drawn in red the two routes down into the canyon. The one on the left is the prominent trail into Coyote Canyon. The steep route on the right has quicker access to/from the Escalante River but their is some scrambling involved and some groups may feel more comfortable with a rope.


The long hike back to the car on 40 Mile Bench.

Coyote is one of the more beautiful canyons in the Escalante but the secret is out. Fortunately, the long arduous hike holds back most the hordes. Its a great introduction for first time desert backpackers. A little route finding and rope work but nothing intimidating.