The gypsum outcrops that are found around the state of Nuevo León in Mexico are famous for the many unique plants which are endemic to them. Gypsum soils occupy large areas of Nuevo León and host a lot of biological diversity. It seems that each year some new species is being described that can only be found on these gypsum outcrops. In fact, a few of the cacti that I wanted to see were examples of plants found nowhere else in the world outside a gypsum outcrop in Nuevo León.
Finding Brahea decumbens and Brahea dulcis growing on one of these gypsum outcrops was never part of the plan for day 3 of my very busy 4-day trip around Monterrey and Nuevo León. This day, Geohintonia mexicana and Aztekium hintonii was to be the highlight, with many other great plants to see along the way. Day 3 in Mexico would prove to be the longest for me as well. With a 7 AM start time, I would not get back to my hotel until 12 AM. A lot of driving was needed to hit the plant stops in Rayones, Galeana and outside Linares.
This blog post picks up at about 2 PM of our day 3 trip, the point at which we reach the gypsum soils and drive through the outcrops between Galeana and Linares.
There was nothing out of the ordinary to start. The very common Yucca filifera can be found growing all over Nuevo León, and it could also be found here on the gypsum soil.
Some Yucca filifera grew quite massive.
Yucca carnerosana could be found here too. The easiest way to tell the two species apart is that Yucca carnerosana never holds green leaves below the perpendicular.
It has a much more upright head of leaves, as this flowering Yucca carnerosana shows.
Agave striata was very common in many parts of the area. In the picture below, you can also see the white coloration of the gypsum soils exposed.
Some Agave striata were quite colorful when under stress.
Echinocactus platyacanthus and Agave striata. Echinocactus platyacanthus is a very adaptable cactus and can be found growing throughout central Mexico, including in gypsum soils. The common name is the Candy Barrel Cactus because the pith of Echinocactus platyacanthus is boiled to make a very popular traditional candy. Thousands of Echinocactus platyacanthus are harvested yearly and it has put the plant at risk in habitat.
I was just a few days too early to see the flowers open on this beautifully colored Ferocactus pilosus.
Agave americana on gypsum soil.
Before starting our drive down into the deep valley to see Geohintonia mexicana and Aztekium hintonii, I found a beautiful flowering tree. It took me a while to ID it, as I wouldn’t have expected this species to be found as far south as Linares, MX. It was a Cercis canadensis var. mexicana (Mexican Redbud).
To see Geohintonia mexicana and Aztekium hintonii, you must drop down from the higher elevation on Highway 58 and into the valley below. You lose a lot of elevation driving down the dirt road that takes you through a massive gypsum outcrop on your way to Geohintonia mexicana. The landscape changes quite drastically, as you can see in the photos below of the gypsum hills with large colonies of Yucca carnerosana on them. Another trait that separates Yucca carnerosana from Yucca filifera is that they do not branch, and this can be seen more clearly in the second photo below
About halfway down the descent into the valley, I spotted the first palms on the gypsum outcrop. A total surprise. Outside the Brahea berlandieri (yes, I know it is now lumped under Brahea dulcis – but I don’t believe it) that were well out of reach growing high into the peaks and cliffs of the limestone ridges, I didn’t see any other native palms the other days out touring. These palms were an added bonus to our extremely busy day.
It didn’t take long to identify the first palm I came upon. No other palm tree looks like it or grows like it in Mexico. It was Brahea decumbens. The species name “decumbens” is the Latin word for “decumbent” – meaning “(of a plant or part of a plant) lying along the ground or along a surface, with the extremity curving upward.” Brahea decumbens does not grow a trunk like a traditional palm tree, which grows straight up. Brahea decumbens trunks lie along the ground. This is how these palms below were all growing. The erect leaves, blue coloration of the leaves on top and bottom, and the fact all these palms were clustering also helped make this an easy palm to identify.
Brahea decumbens in flower.
Brahea decumbens and Agave striata in front.
This was my favorite sighting of Brahea decumbens. This photo gives you a better understanding of how the palm grows by the trunk lying on the ground. This one has started to grow over the cut in the road. This is a very old palm tree shown below. The base of the trunk of this Brahea decumbens still went another 5 feet or so back from what you see in the photograph.
Brahea decumbens was not alone. It shared its habitat with another palm – Brahea dulcis. This gypsum outcrop environment they shared can be seen below. You will also notice the intercalation of limestone rock, like the ridge at the top of the photo.
Brahea dulcis is a variable palm tree thanks to its extended growing range from Northern Mexico down into Guatemala. While it can be found clustering (rarely), it is typically a solitary palm; one which, unlike Brahea decumbens, grows with a usual upright stem like most other palm trees around the world.
Brahea dulcis in flower. Note the thicker flower spathe and the tomentum on it. Traits that separate the flower from the Brahea decumbens shown earlier.
A young Brahea dulcis. At this early stage they could be confused for Brahea decumbens.
A group of Brahea dulcis growing in gypsum soil next to exposed limestone.
Yours truly caught in a moment of drool.
Another interesting fact about Brahea dulcis is that there are two leaf color forms. One that is green and another that is blue. In the next two photos you can see the two leaf color forms growing right next to each other.
A closeup of the green leaf form.
The level of glaucousness that the blue leaf form Brahea dulcis can display varies. This one below was almost white.
It wasn’t hard to spot Brahea dulcis in the landscape.
So I mentioned early in my post that finding these two palm tree species in the area was a surprise.
Because Brahea decumbens is usually only found growing on exposed limestone and not on gypsum outcrops like this. Brahea dulcis typically prefers growing on limestone hills and ridges as well, although as pointed out earlier, it has a much broader range and can be found elsewhere away from limestone.
Why is this noteworthy? Aren’t gypsum and limestone basically the same thing?
No. Even though both gypsum and limestone come from old marine environments, their properties are different. Gypsum is calcium sulfate (CaSO4·2H2O) and is mainly deposited from sea water. Gypsum is a neutral mineral, so it doesn’t change soil pH. Limestone has a main constituent Calcium carbonate (CaCO3) and is a type of sedimentary rock – the skeletal fragments of marine organisms. Limestone is alkaline. Gypsum is more soluble than limestone, so the outcrops are never as impressive as the limestone spines found in Huasteca Canyon, for example. Much of the gypsum outcrops around Nuevo León occur along the flanks of the limestone ridges.
I would have loved to explored further the gypsum outcrop where I found Brahea decumbens and Brahea dulcis growing, but it was getting late and we still had to finish driving down the mountain to find Geohintonia mexicana and Aztekium hintonii. During our descent we ran into a road block. We had to wait for this goat herder to clear the road. Unfortunately, open range goat herding it devastating many habitats of rare flora throughout Mexico. The second photo below shows how much of an impact these goats can have on the landscape.
Not long after we passed the goat herder we reached the location where Geohintonia mexicana and Aztekium hintonii could be found. They grow together along the sides of washes in these gypsum canyons.
Along the hike to get down into the washes, I saw a few new cactus species I hadn’t seen prior. (In total I would end up seeing just over 45 different cactus species in 4 days with Miguel my guide.) The first was Neolloydia conoidea and the second was Echinocereus parkeri.
At dusk we reached the location where Miguel had seen hundreds of Geohintonia mexicana and Aztekium hintonii years before when he was last there. I was looking forward to seeing these “hundreds” like some online photos showed. Sadly, unscrupulous people have been aggressively poaching the plants from this location for many years now. Miguel told me the biggest offenders come from the Czech Republic and China. Even though both Geohintonia mexicana and Aztekium hintonii are protected species, the poachers have honed their skills perfectly to bribe and sneak their loot out of Mexico. I expected to find a heavily populated area, instead I only found one of each plant! That was it. And I found those two plants only because I am good at Easter egg hunts and climbed to get the photographs.
The photos above are pretty grainy and a bit out of focus, as they were taken at dusk under very little light. In fact, our walk back to the car had to be done with headlamps. So to be fair, I know there are many more Geohintonia mexicana and Aztekium hintonii to be found had I explored much deeper into the washes. I plan to come back to this area in November, as I can’t leave the bad taste in my mouth. However, unlike another plant I saw in the wild that poachers love to take, Agave albopilosa, these are not growing on inaccessible areas of a cliff. So I imagine if things continue as they are, Geohintonia mexicana and Aztekium hintonii won’t be found in the wild much longer.
One final note on the situation where Geohintonia mexicana and Aztekium hintonii reside. Recall the goat herder in an earlier photograph above. Well apparently he just isn’t any goat herder. He works for the local community to protect the plants. In fact, he wouldn’t let us leave unless we each paid $18 USD – if you know what I mean. For a guy meant to protect the area, he had no interest in looking in our backpacks filled with camera gear. I could have been taking out 20-30 plants in my pack instead of carrying my camera gear. I realized then that the $18 is a fair price for a poacher to pay to have a local turn a blind eye. To me and Miguel it was just a shakedown.
That concludes my Day 3 adventure around Nuevo León. Another amazing day in a beautiful country with so much to offer. I grow Brahea decumbens in my garden, so accidentally running into it in habitat was quite the thrill.