The Barranca de Tolimán is situated to the northwest of Zimapán in southwestern Hidalgo, and is the site of an active mine with large trucks rumbling up and down the steep, narrow dirt road that connects the mine to the town of Zimapán and beyond. This past May, I made my third voyage to the Barranca de Tolimán and was, once again, blown away by its sheer size and incredible vistas. The drive from Zimapán down to the bottom of the barranca is roughly 15 KM long with a series of tight switchbacks towards the end that rapidly take you down in elevation until bottoming out near the mining setup. As you travel these switchbacks, take a moment to soak up the incredible vistas out over the many deep barrancas formed by the smaller rivers that drain into the Rio Moctezuma. Driving the switchbacks can be a scary adventure since you share the road with the big mining trucks that constantly travel the narrow, dirt road. Fortunately, there are wide spots along the road to allow two vehicles to pass. Unfortunately, it feels like you are never near one of those wide spots when a truck is approaching, so make sure you look way down or up the road and if you see a truck coming, pull over and let it pass.
When you reach the bottom, hike around as we see Brian Kemble doing in the picture below. This is a beautiful spot to take shots of the canyon walls replete with an amazing array of plants.
In the shot below, we see a rock slope filled with Hechtia argentea
Climb up the slopes and get an up close and personal view of the marvelous and wonderful plants. Below, we see Agave xylonacantha growing on the limestone rock, its favorite substrate. You knew this gallery would start with an agave didn’t you? You can find this for sale in the store.
How about Echeveria tolimanensis (also available in the store) with the intricate bud brinting etched into the gray bloom overlaying the purplish green leaves. See more pictures and the original description in crassulaceae.com.
There are a couple of spectacular Mammilarias in the canyon also. The first one pictured is Mammillaria elongata and the next one is Mammillaria geminispina.
Next we see two species of Ferocactus. the first one pictured is Ferocactus echidne and the next shot shows Ferocactus glaucescens in the foreground and F. echidne behind. The third shot shows a closer shot of Ferocctus glaucescens. Notice how these all seem to be perched precariously on the edge of a sharp-edged limestone projection.
When Brian Kemble and I visited the Barranca de Toliman in 2010, we saw these plants and one of his comments is that this is thought to be the type locality for Hechtia argentea and having seen these, I would say that they fit the description. When I grow these plants from the seed, the young ones have green leaves with very little of the glaucous white bloom on them, but frequently having purplish red on the tips. As the plants age, the develop more of the glaucous white bloom characteristic of the mature plants.
I would like to leave you with shots of the spectacular Yucca queretaroensis that can be seen by the thousands on the slopes of this barranca system. There are so many of these in such a famous locality that it is unimaginable for it to have gone undescribed for so long. However, in three trips to the canyon and other areas where this species grows, I have yet to see any plants in bloom or with any fruits on them. I have seen a couple of plants with really old inflorescences, but so many plants out there one would expect to see fields of blooms as is the case with many of the other Yucca species. For more photos and musings on Yucca queretaroensis go to part 1 and part 2.
I hope you enjoyed this brief tour of the Barranca de Toliman and will be able to visit the incredible beauty of this place sometime.