April 11, 2018 by mattbuckinghamphotography

The Biodiversity of the Rio Grande Valley Part 2: The Cacti

Peyote

Spring in the Tamaulipan Thornscrub is a beautiful, albeit deceiving thing. When the chaparro, huisachillo, and guayacan bloom above a carpet of wildflowers, its easy to forget just what a harsh, unforgiving land this can be. I was bleeding through my jeans when I sat a moment to rest in the shade of a mesquite tree. I don’t think that Carolina, James, or Erin had fared much better. Despite being early March, it was pushing 90 degrees, and the sun was beating down. After taking a long draw from my water bottle, I got up and continued my search. I winced as I pushed through the allthorn, and felt the tasajillo spines pierce my skin. It’s safe to say at that point my spirits weren’t at their highest. But then I heard the voice of my wife as she called out, “I found one, with a flower!” In that moment, pain seemed like an insignificant consideration as I pushed through the tangle of thorns that lay between me and my succulent quarry. I saw Carolina squatting down looking at the base of a large shrub. There, under the shade and protection of a condalia I could see the iconic Peyote in bloom.

Despite being very un-cactus like, the Peyote may be the famous of all cacti. Once fairly common in parts of south and west Texas, decades of over-harvest, poaching, and habitat loss of significantly reduced the populations to the point that today they are a rare sight among the thornscrub. The reason that it has been so persecuted is the psychoactive compound mescaline contained within its flesh.

In fact, Peyote is one of the most well known psychoactive plants. It has been utilized for centuries by native peoples for both its medicinal and hallucinogenic effects. Today Peyote is a controlled substance in the United States due to its use as a recreational drug. It is, however, legal for many native tribes to harvest and consume for ritualistic purposes. And though it may be illegal to harvest or possess, poachers continue to devastate Peyote populations to sell them on the black market.

In the United States Peyote is known only from extreme southern and western Texas. Here it occurs in desert scrub and arid brushland, typically growing beneath dense shrubs. It is one of three spineless cacti in Texas. We were lucky enough to observe some in bloom on an extensive private ranch in the Tamaulipan Thornscrub of South Texas, with the help of our dear friends Toby Hibbits and Connor Adams.

Peyote

In our pursuit of Peyote we observed several other species growing beneath the shelter of their nurse plants. We seemed to catch the Heyder’s Pincushion Cactus (Mammillaria heyderi) in full bloom. This small cactus grows low to the ground, and like many species with this growth habit, is very difficult to spot when not in bloom. In the early spring a single plant may put on a dozen or more flowers, generally organized in a ring along the top of the cactus. It occurs from Mexico through south and central Texas west across eastern and southern New Mexico into southern Arizona.

Heyder’s Pincushion Cactus

While the Heyder’s Pincushion Cactus may be difficult to spot when not in bloom, the Hair-covered Cactus (Mammillaria prolifera) is difficult to spot even when in flower. This species is tiny, with individual stems not much larger than an egg, though they may occasionally form large clumps. The Hair-covered Cactus is known in the United States only from Texas, where it occurs in only a handful of counties in southern and south-central Texas, most of them along the Rio Grande.

Hair-covered Cactus

Though it is superficially similar to the Mammillaria prolifera, the Runyon’s Pincushion Cactus (Coryphantha pottsiana) is easily differentiate when in flower. Like many species of cactus, the taxonomy for Coryphantha pottsiana is a bit cloudy. It has variably been known as Coryphantha robertii, Mammillaria robertii, Mammillaria bella, Escobaria bella, Escobaria runyonii, and Escobaria emskoetteriana. Some authorities still use the latter, though Coryphantha pottsiana seems to be more widely accepted. The Runyon’s Pincushion Cactus is known from northern Mexico and a few Texas Counties along the Rio Grande, where it is generally uncommon.

Runyon’s Pincushion Cactus

While the previous cacti are generally small, the Horse Crippler (Echinocactus texensis) can reach much larger proportions. While most seem to be about the size of a basketball, we saw some that were easily 3 or 4 times as large. They tend to occur in looser soil including sandy alluvium. They are also frequently found growing in the open, away from nurse plants, though its likely that many plants get their start in the less hostile microclimate of a nurse plant. Their impressive spines seem to be an effective deterrent against mammalian predators.

Horse Crippler

Among the most beautiful of all cacti are the hedgehog cacti of the genus Echinocereus, a few of which are endemic to the Tamaulipan Thornscrub of South Texas and northern Mexico. This year our trip coincided with the peak bloom of Echinocereus fitchii, the Fitch’s Hedgehog Cactus. Though they are generally hard to find, in the right habitat they can be abundant, and we saw dozens, blazing the thornscrub with their pink blooms. Like Coryphantha pottsiana and so many other cactus taxa, the taxonomy of Echinocereus fitchii is murky at best. It is considered by many to be a subspecies of the more broadly distributed Echinocereus reichenbachii. For anyone interested in the topic I strongly recommend reading “A hard-to-manage taxon: The Black Lace Cactus (Echinocereus fitchii ssp. albertii)“. Though it discusses the Fitch’s Hedgehog Cactus’s Federally Endangered cousin, it includes a good discussion on the taxonomy of E. fitchii and E. reichenbachii, including characteristics used to distinguish the two.

Fitch’s Hedgehog Cactus

In my opinion, the Lady Finger Cactus (Echinocereus pentalophus) is perhaps the most spectacular cactus native to the United States. Confined to northern Mexico and extreme southern Texas, they can form huge mats under the shade of mesquite and other trees and large shrubs. They have even been found growing upon protected ridges adjacent to the Laguna Madre. Their bright blooms shine neon pink under the midday sun.

Lady Finger Cactus

The bizarre Pencil Cactus (Echinocereus pentalophus) seems less a cactus and more a tangle of dried branches resting at the base of some thorny shrub. That is, until it’s giant pink blooms open in the early spring and betray its presence to the world. Unlike most other members of its genus, the Pencil Cactus produces a massive tuberous roots that aid in water storage.

Pencil Cactus

The highlight our South Texas cactus hunt, however, was finding the Federally Endangered Star Cactus (Astrophytum asterias) in peak bloom, an experience which I will share in my next blog post.

Star Cactus

April 6, 2017 by mattbuckinghamphotography

Spring in the Hill Country

Giant Spiderwort on a granite outcrop

Three springs ago I was lucky enough to marry the love of my life. Before and since Carolina and I have shared many adventures in the natural world. It seemed fitting that we spend our anniversary in these wild places we love so much, so we decided to take a trip to the Texas Hill Country. It had been years since I spent any time exploring this treasure trove of natural wonders, and Carolina had only previously passed through. We looked forward to a trip full of searching for rocks, gems, wildflowers, and other wild things.

The rugged Texas Hill Country is part of the Edward’s Plateau, an extensive uplift in central Texas comprised of marine deposit that are 100 million years old or more. The region is primarily comprised of limestone, however extensive granite outcrops are present in areas. The variety of substrates harbors an incredible array of plant and animal species, many of which are found nowhere else in the world. Perhaps no other part of the state is as uniquely Texan as the Hill Country. The following blog post is a long one that highlights its natural beauty.

Spring in the Texas Hill Country

We covered a lot of ground during our trip, trying to see as much as we possibly could. Recent rains had swollen the clear streams of the region. While hiking we came across this tributary of the Colorado River, which I suspect is normally fairly tame. We enjoyed a swim in the cool, clear waters below the fall.

A Hill Country Waterfall

The wild’s of the Hill Country are full of beautiful sights, like this gnarled live oak growing from the top of a massive granite boulder.

A gnarled live oak takes hold on a granite outcrop

The Texas Bluebonnet (Lupinus texensis) is certainly the most iconic of all Texas wildflowers. While I can’t deny their beauty, I am usually reluctant to photograph bluebonnets, as they have been so extensively planted that it’s hard to know when one has encountered a truly wild population. I found this large population in a clearing in an open oak/mesquite savannah far from any roads or developed areas, and am fairly certain it is a native population.

Texas Bluebonnets

We were lucky that a number of cacti had begun to bloom during our trip. I posted about the Claret Cup Cactus (Echinocereus coccineus) in my previous blog. I also mentioned the Lace Cactus (Echinocereus reichenbachii). The latter deserves mention again here, as we found many in bloom while we were driving back roads in pursuit of Topaz and Celestite. While we did not find the precious stones, we were rewarded with the brilliant blooms of this spectacular cactus. The largest, most impressive individuals and groups were on private land well behind fences, however we did find several beautiful individuals within camera range.

A Lace Cactus clings to a granite outcrop

Lace Cactus

We also found a few Heyder’s Pincushion Cactuses (Mammillaria heyderi), which I had recently photographed in South Texas.

Heyder’s Pincushion Cactus

Perhaps one of the most spectacular wildflower displays came from the Giant Spiderwort (Tradescantia gigantea) which seemed to thrive on granite and limestone alike.

Giant Spiderwort

We observed a number of Penstemon species. The most common and widespread was the Prairie Penstemon (Penstemon cobaea). It was a treat to see such large, healthy populations of this species, as it is rare in the Pineywoods.

Prairie Penstemon

We even found a few Prairie Penstemons with a striking lavender wash.

Prairie Penstemon

We also found the much less common Guadalupe Penstemon, which is endemic to the Texas Hill Country.

Guadalupe Penstemon

County level distribution for Penstemon guadalupensis from http://www.bonap.org. Yellow counties indicate that the species is present but rare.

The most spectacular of the Penstemons, however, was the Hill Country Penstemon (Penstemon triflorus), another Edward’s Plateau endemic.

Hill Country Penstemon

County-level distribution for Penstemon triflorus from http://www.bonap.org.

The Fringed Bluestar (Amsonia ciliata) was fairly difficult to spot among the grasslands and oak savannahs, despite its bright blue blooms.

Fringed Bluestar

The Green Milkweed Vine (Matelea reticulata) is native to Texas and northeastern Mexico. It is easy to see where it gets one of its alternate common names: The Pearl Milkweed Vine.

Green Milkweed Vine

After spending a couple of nights camping we visited our good friends Scott Wahlberg and Ashley Tubbs in Kerrville. Scott and I are known for our absurd conversations and hypothetical scenarios. We are lucky that we have such tolerant women to put up with our shenanigans. After spending the night at their place, they showed us a beautiful series of canyons that had eroded into the limestone hills. The Endangered Golden-Cheeked Warbler (Setophaga chrysoparia) serenaded us as we explored its domain.

In addition to being rich in endemics, the Texas Hill Country is home to many species typical of the central or Eastern United States that are disjunct from the main portion of their range. These species generally exist in these cool, moist canyons and are relicts of cooler, wetter times. Scott has found Western Slimy Salamanders (Plethodon albagula) here. Luckily I had seen them in the Hill Country before, as we were unable to find any this trip. We did, however, see several Eastern Red Columbine (Aquilegia canadensis) in bloom.

Eastern Red Columbine

We observed several False Day Flowers (Tinantia anomala) in bloom. These bizarre blooms reminded me of some alien creature.

False Day Flower

We also found another uncommon endemic growing in these canyons: The Scarlet Clematis (Clematis texensis).

Scarlet Clematis

County-level distribution for Clematis texensis. Yellow counties indicate that the species is present but rare.

The Texas Madrone (Arbutus xalapensis) is a typical tree of the slopes grading into these canyons. We were lucky to find a few in bloom.

Texas Madrone

With all of the wildflowers in bloom, the pollinators were out in force as well. Perhaps the most beautiful, and definitely the most cooperative were the many Juniper Hairstreaks (Callophrys gryneus) that we observed.

Juniper Hairstreak

As is so often the case for me, as the trip came to an end I was hit with a feeling of sadness. But it’s hard to be too sad when I was returning to the Pineywoods, where so many interesting species were awaiting me.

March 27, 2017 by mattbuckinghamphotography

South Texas Part III: The Lady and the Pencil

Lady Finger Alicoche

Though the Trans Pecos is the center of cacti diversity for Texas, the cactus community of the Tamaulipan thornscrub is no less spectacular. It includes a number of Mexican species that just barely enter the states in extreme South Texas. Two species in particular, have been on my bucket list for years now: the Lady Finger Alicoche (Echinocereus pentalophus) and the Pencil Cactus (Echinocereus poselgeri). I would have included them on my 2017 biodiversity list, however I didn’t anticipate taking a trip to South Texas this year. So when a march trip to Big Bend fell through, I delighted in the opportunity to finally observe these species in their natural setting.

This is the part of the story where the patience of Carolina, my parents, and my brother really come into play. They waited patiently while I sought out and photographed these species, and even helped me in my endeavor. Carolina has a real interest in cacti as well, and she enjoyed seeing so many species in bloom.

Lady-Finger Alicoche

The Alicoche is a cactus of the Tamaulipan thornscrub of northeastern Mexico and South Texas. It can form large mats under the shade of nurse plants, however its stems are relatively nondescript, and the plant itself is difficult to see when not in bloom. When it blooms, however, its gives its presence away in spectacular fashion. The huge pink blooms seem to explore from the thornscrub. It is easily one of the most spectacular plants I have ever had the good fortune to observe.

County-level distribution of Echinocereus pentalophus from http://www.bonap.org. Yellow counties indicate that the species is present and rare.

I found the Lady Finger to be an extremely photogenic plant, lending itself both to portraits of the blooms and landscape shots featuring the plant as a foreground element. We were fortunate to observe many individuals in many different settings throughout the trip. Spending time with this species was a truly memorable experience that I look forward to repeating some day in the future.

Lady Finger Alicoche

Remnant Tamaulipan thornscrub forest with Lady Finger Alicoche in bloom.

Fortunately the Alicoche was fairly easy to find. That was not the case with the Pencil Cactus. If the Lady Finger is hard to see when not flowering, the Pencil Cactus is virtually impossible. Also known as the Sacasil or Dahlia Hedgehog Cactus, the Pencil Cactus has an extremely narrow stem that does not look much different than a stick. Couple that with their tendency to grow among dense tangles beneath thornscrub shrubs, and you could imagine how hard it would be to pick them out. When they bloom, however, the light up the thornscrub.

I spent a large part of the trip looking for this species in vain. I went to sites where others had seen them, and scoured seemingly suitable habitat. I did not see one until late afternoon on our last day in the valley. After trudging through the dense thornscrub, cut, tired, and full of spines from allthorn, mesquite, and prickly pears I was ready to give up. Then, as we were preparing to leave, driving through an undeveloped area adjacent to a small subdivision Carolina shouted “STOP! The Pencil Cactus!”. I looked up and saw it. It’s flower had been nipped off. Disappointed, I looked around hoping that there might be another in the area, and then I saw it up a steep slope. I grabbed my camera and scrambled up the slope. As my shutter clicked I felt a real sense of contentment, both in having found the Pencil Cactus, and that I have such a wonderful family that indulges my passion and obsession for the natural world.

Pencil Cactus

The range of the Pencil Cactus is virtually the same as that of the Lady Finger. It seems to be found in slightly denser clumps of brush where its slender, fragile stem can lean on the limbs of nurse plants for support.

County-level distribution for Echinocereus poselgeri from http://www.bonap.org. Yellow counties indicate that the species is present and rare.

We were lucky enough to observe two other species of Echinocereus in bloom in our pursuit of the Lady and the Pencil. The Strawberry Pitaya (Echinocereus enneacanthus) was abundant throughout much of the thornscrub. We were a bit early in the season to see many flowers, but I was lucky enough to spot a few in bloom. E. enneacanthus is a fairly widespread species throughout much of Mexico and southern and western Texas and New Mexico. The variety in South Texas is Echinocereus enneacanthus var. brevispinus, identifiable by its short spines.

Strawberry Pitaya

Much less common was the Fitch’s Hedgehog Cactus (Echinocereus fitchii). E. fitchii was initially, and still is considered by some to be a variety of Echinocereus reichenbachii, the Lace Cactus. There are significant differences between the two, however, including root structure and spine and flower characteristics. Most cactus flowers are at their best midday on sunny days. This makes photographing them a challenge, as shading them often takes away some of the brilliance of their blooms.

Fitch’s Hedgehog Cactus

Most of the cacti we observed during our trip were on Nature Conservancy property. I can’t say enough good things about the Nature Conservancy in Texas. I will discuss the Nature Conservancy and their contributions to conservation in my next blog post, but wanted to mention them here, as one afternoon Seth and I took a hike at one of their South Texas preserves. We saw more cacti on this hike than the rest of the trip combined. Echinocereus pentalophus and E. enneacanthus were abundant, as were Texas Prickly Pear (Opuntia lindheimeri) and Dog Cholla (Grusonia schotii). We also observed Christmas Cholla (Cylindropuntia leptocaulis) and Lower Rio Grande Valley Barrel Cactus (Ferocactus hamatacanthus var. sinuatus), though none were in bloom. We were, however, fortunate enough to see three other species in bloom: Heyder’s Pincushion Cactus (Mammillaria heyderi), Hair-Covered Cactus (Mammillaria prolifera), and Twisted-Rib Cactus (Hamatocactus bicolor).

Heyder’s Pincushion Cactus

Hair-Covered Cactus

Twisted-Rub Cactus

We also observed several other interesting plants in the thornscrub. Some of these have been covered in previous blog posts. Others I didn’t photograph for various reasons. One of the most interesting was the terrestrial bromeliad Gaupilla (Hechtia glomerata). We also observed a number of birds typical of the desert southwest, including Pyrrhuloxia (Cardinalis sinuatis), Black-throated Sparrows (Amphispiza bilineata) and Cactus Wrens (Campylorhynchus brunneicapillus). At one point I flipped over a dried cow patty and found a little Western Narrowmouth Toad (Gastrophryne olivacea) sheltering in some remnant moisture beneath it.

Western Narrowmouth Toad

Stay tuned for more cactus-seeking adventures in my next blog entry.

March 23, 2017 by mattbuckinghamphotography

South Texas Part II: Into the Thornscrub

Common Pauraque

Beyond the South Texas coastal dunes, marshes, and prairies lies a unique, biodiverse community dominated by a variety of shrubs and small trees. Variably referred to as South Texas brush country, mezquital, and Tamaulipan thornscrub, this semi-arid, subtropical community occurs in South Texas and the Mexican states of Tamaulipas, Nuevo Leon, and Coahuila. It is home to plants and animals found nowhere else on earth, and in South Texas, marks the northern extent of several Latin American species that just barely enter the United States.

Tamaulipan Thornscrub with blooming Lady Finger Alicoche alongside Strawberry Pitaya.

The Tamaulipan thornscrub in the Rio Grande Valley of South Texas is one of the United State’s premier birding locations. My parents and I have made a number of birding trips here in the past, drawn in by the promise of catching a glimpse of one of these South Texas specialties. During this trip the birding was fairly slow, but we did see many of the typical Rio Grande Valley species including Plain Chachalacas (Ortalis vetula), White-tipped Doves (Leptotila verreauxi), Green Jays (Cyanocorax yncas), Long-billed Thrashers (Toxostoma longirostre), Altamira Orioles (Icterus gularis), and Olive Sparrows (Arremonops rufivirgatus). Unfortunately these species did not present me with any good photo ops. I did luck out, however, when we found another Valley specialist, the Common Pauraque (Nyctidromus albicollis) roosting alongside a trail. These members of the nightjar family are nocturnal and rely on their camouflage to roost on the ground during the day. It was nearly invisible among the dried leaves and sticks littering the earth. I utilized the dense natural debris to create the window effect seen on the photo at the start of this blog entry.

Many mammal species also reach the northern extent of their range in deep South Texas. Unfortunately many of them are now gone. The last Jaguar (Panthera onca) in Texas was killed in the Tamaulipan thornscrub in the 1940’s. There are some that still hold onto hope that there may be a few Jaguarundi left in the Rio Grande Valley. Though there have been no verified sightings in many years, there have been unverified reports. Ocelots (Leopardus pardalis) are still hanging on in the brush country, though they are now rare, and protected under the Endangered Species Act. In our explorations of the thornscrub we observed a number of mammals including White-tailed Deer (Odocoileus virginianus) and Collared Peccaries a.k.a. Javelinas (Tayassu tajacu). The only mammal I was able to photograph was the little Eastern Cottontail (Sylvilagus floridanus) pictured below.

Eastern Cottontail

There are many reptile and amphibians whose United States distribution is also limited to the Rio Grande Valley. Being an amphibian enthusiast, I was disappointed that we missed the heavy rains that brought out such rarities as the Mexican Burrowing Toad (Rhinophrynus dorsalis) and White-lipped Frog (Leptodactylus fragilis) by just a couple of days. These species are explosive breeders that emerge to breed after heavy rains. I did spend some time looking for the beautiful Speckled Racer (Drymobius margaritiferus), a primarily Latin American species that is known from only a couple of sites in South Texas. I struck out on the snakes, but was able to photograph a couple of the areas conspicuous lizards: the Texas Spiny Lizard (Sceloporus olivaceus) and the Rose-bellied Lizard (Sceloporus variabilis).

Texas Spiny Lizard

Rose-bellied Lizard

The Rio Grande Valley is also world famous for its butterflies. While we observed many species, the only one I obtained a decent photo of was the Common Mestra (Mestra amymone).

Common Mestra

The Tamaulipan thornscrub is named for the typically thorny shrubs and small trees that dominate the community. Typical species of this community include Mesquite (Prosopis gladulosa), Chaparro (Ziziphus obtusifolia), Whitebrush (Aloysia gratissima), Texas Paloverde (Parkinsonia texana), Texas goatbush (Castela erecta), Saffron Plum (Sideroxylon celastrinum), Blackbrush Acacia (Vachellia rigidula), Corona de Cristo (Koeberlina spinosa), Guayacan (Guaiacum angustifolium), and Ebano (Ebenopsis ebano). These shrubs form often impenetrable thickets. On some sites, particularly as one moves further west in the Rio Grand Valley the shrubs may become more scattered, forming dense clumps with areas of exposed gravel and caliche. It was in areas such as this where we observed the rare Baretta (Helietta parvifolia).

Texas Paloverde

Occasionally growing in the crooks of mature Ebano, a real botanical treasure can be found. The epiphytic bromeliad Tillandsia baileyi, commonly known as Bailey’s Ball Moss barely enters the United States in South Texas, where it is rare. It is much more striking than other members of its genus, which includes the familiar Spanish Moss (Tillandsia usneoides).

Bailey’s Ball Moss

A conspicuous component of the South Texas brush country is the Anacahuita or Mexican Olive (Cordia boissieri). Its bright blooms illuminate the native brushlands, and it is a popular native ornamental in South Texas. The tree was reportedly utilized by native cultures and Spanish settlers to make jellies and dyes. The leaves can be brewed in a tea that may help with rheumatism and various ailments of the lungs.

Anacahuita

Many invertebrates can be found utilizing Anacahuita leaves and flowers. The Wild Olive Tortoise Beetle (Physonota alutacea) is found exclusively on these small trees.

Wild Olive Tortoise Beetle

Many pollinators also frequent the blooms. They due so at their own risk, however, because predators lurk beneath these flowers. We observed this crab spider (Mecaphesa sp.) awaiting an unsuspecting victim.

Crab Spider

South Texas is also home to a variety of native lantana species. Brushland lantana (Lantana achyranthifolia) could occasionally be found scattered about the thornscrub.

Brushland Lantana

We also observed a couple of species of heliotrope, including the widespread Seaside Heliotrope (Heliotropium curassivicum), and the more range restricted Scorpion Tail (Heliotropium angiospermum) which occurs in South Texas and southern Florida.

Seaside Heliotrope

Scorpion Tail

Fiddleleaf Tobacco (Nicotiana repanda), a species of central and southern Texas, was also fairly common.

Fiddleleaf Tobacco

Shrubby Blue Sage (Salvia ballotiflora) occurs in the U.S. only in southern and western Texas.

Shrubby Blue Sage

Over the millennia, the meanders of the Rio Grande has slowly changed course, leaving in their wake old depressional oxbow scars. The scars eventually filled with rainwater and runoff and developed a unique flora. Known as Resacas these unique wetlands provide habitat for a host of rare plant and animal species. We observed many Least Grebes (Tachybaptus domincus), another bird species whose U.S. distribution is restricted to South Texas in them. We also observed the rare Runyon’s Water-Willow (Justicia pacifica) here.

Runyon’s Water Willow

As one moves further west along the valley, one begins to notice more and more of a desert influence. I observed many familiar species that I have photographed in West Texas including Snapdragon Vine (Maurandella antirrhiniflora) and Cenizo (Leucophyllum frutescens). The latter blooms in response to rainfall and humidity.

Snapdragon Vine

Cenizo

I observed Purple Groundcherry (Quincula lobata) here. These showy groundcover primarily occur in the southwestern United States.

Purple Groundcherry

I also observed Bearded Prairie-Clover (Dalea pogonathera) here. This member of the pea family is primarily a species of the Chihuahuan Desert.

Bearded Dalea

South Texas is also home to a few woodsorrel species that do not have the typical “lucky clover” leaf. Pictured here is Peonyleaf Woodsorrel (Oxalis dichondrifolia).

Peonyleaf Woodsorrel

The open caliche hills were home to the beautiful Berlandier’s Nettlespurge (Jatropha cathartica), which is restricted to South Texas and adjacent Mexico.

Berlandier’s Nettlespurge

The most spectacular element of the Tamaulipan thornscrub, however, were the cacti. These famed succulents were my main target in South Texas, and I was fortunate to observe many species. Though my next two blog posts will be dedicated to the incredible diversity of South Texas cacti, I have decided to provide a preview of things to come below.