Hidden Wonders in the Forests of Northeast Texas

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Rich Hardwood Forest

Target Species: 

Tapertip Trillium (Trillium viridescens)

Downy Yellow Violet (Viola pubescens)

It’s been some time since I’ve posted about one of my “Biodiversity Targets”, those species that I included on my 2017 list of biodiversity goals.  At the end of 2017, I had only tracked down around half of the species on that list, but along the way I amassed a wealth of incredible observations, adventures, and experienced more of our states biodiversity than I ever could have imagined.  So I decided that instead of creating a new list or adding to the existing list, I would work over the next couple of years to finish the list I made at the start of 2017; a list that was a bit more ambitious than I had anticipated.

In early April 2018 my pursuit of these species would take me to the far northeast corner of Texas, near the Oklahoma border in search of two species that I have long wanted to see in the state.  Joining me in this quest was my friend Scott Wahlberg.  We set out early, in the gray of a perfect spring morning.

The counties of far northeast Texas feature a mingling of habitats typical of both the Post Oak Savannah and Pineywoods.  Some communities, like the rich hardwood forests of the Sulphur River and Red River and their tributaries are unique to this part of Texas, and more similar to the forests of the Ouachita Mountains of Oklahoma and Arkansas than they are to those of the heart of the Pineywoods in Deep East Texas.  Here a sweet of species reach the southwestern limit of their range.  Among these are several species that are either absent from, or are very scarce elsewhere in the Pineywoods.  Examples of these include trees like Silver Maple (Acer saccharinum), Black Oak (Quercus velutina), Shingle Oak (Quercus imbricaria), and Nutmeg Hickory (Carya myristiciformis).  Examples also include woodlands forbs such as Fire Pink (Silene virginica), Rue Anemone (Thalictrum thalictroides), Downy Yellow Violet (Viola pubescens), Tapertip Trillium (Trillium viridescens), and more.

The latter two were the focus of this trip.  In Texas, Trillium viridescens occurs in rich hardwood forests on steep river bluffs and in the damp alluvium of  riparian woodlands.  Here we found it growing among other interesting woodland forbs like Mayapple (Podophyllum peltatum), Veiny Pea (Lathyrus venosus), Wild Hyacinth (Camassia scilloides), and White Trout Lily (Erythronium albidum).

Trillium viridescens is a species of the central United States, primarily occurring in the Ozark Plateau, and the Boston and Ouachita Mountains. It barely enters Texas in northeastern portion of the state. The plants in the northern portions of its range generally have petals that grade from purple at the base to bright greenish yellow at the tips. Most Texas individuals, however, tend to be solid maroon to greenish purple.

 

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Tapertip Trillium

The sessile-flowered trilliums can be a tricky group. In Texas, three species, T. gracile, T. ludovicianum, and T. viridescens are superficially similar in many ways, however when I first saw T. viridescens in the field it was immediately clear that this species was obviously different from the other two. The T. viridescens plants we observed were much larger and more robust than any T. gracile or T. ludovicianum I had ever seen. Their faintly mottled, broadly ovate leaves were much different than the state’s other trillium species, which have narrower, more heavily mottled leaves. The petals were also much larger. There are other characteristics that can be used to differentiate T. viridescens from the other two species such as a scabrous vs glabrous scape and a number of differences in flower morphology.

Seeing Trillium viridescens in the field certainly left a lasting impression.   It was a special moment for me, as it was the last of our state’s five species of trillium that I had left to see.  Like all of our other trillium species, T. viridescens is at risk, and is likely declining from a number of factors such as climate change and land use conversion.

Viola pubescens another characteristically eastern species that barely enters Texas in the far northeastern part of the state.  It is a yellow-flowered violet that occurs through most also occurs in parts of central United States as far west as the Black Hills of western South Dakota and eastern Wyoming.  While I have seen and photographed this species in the southern Appalachians, I had long wanted to see it in Texas.

On that fine spring day, we found it in a mature riparian forest along a small order stream.  Shaded by an overstory of Silver Maple, Red Maple, Shumard Oak and Sweegtum,  we found it growing alongside a variety of other woodland herb including Podophyllum peltatum, Packera glabella, Packera obovata, Viola sororia, and Erythronium albidum.

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Downy Yellow Violet

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Downy Yellow Violet

While exploring the backgrounds of northeast Texas we spotted several large clumps of Eastern Bluestar (Amsonia tabernaemontana) growing in a remnant prairie.  Scott and I stopped a moment to photograph them, and discussed what the area must have looked like before the hand of man left it forever changed.  We also pondered the possibility that prairie species like the Southern Crawfish Frog might just still hang on here.  Though I haven’t spent much time in this part of the state, I quickly gained an appreciation of just how diverse it really is.

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While most of northeast Texas remains rural and relatively undeveloped, there is little public land, and most of these populations are on private land and vulnerable. There is still hope, however.   Through conservation efforts with and by private landowners there is hope that these lovely members of our flora remains for future generations to enjoy.

The Biodiversity of the Rio Grande Valley Part 4: The Old Man of the Thornscrub

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Our last day in the Rio Grande Valley was a memorable one.  Carolina, Erin, James, and I spent the morning admiring wintering waterfowl in a shallow Resaca.  During the heat of the afternoon we found ourselves among Lady Fingers and other spined succulents.  In the evening we took a relaxing stroll to see what sort of wildlife might emerge from the dense thornscrub.

There were multiple times during the trip when the conversation between James and I turned to the Texas Tortoise (Gopherus berlandieri).  This iconic South Texas species was high on both of our lists, but thus far the lumbering reptile had evaded us.  But as the sun sank low on our final day, there it was, meandering along a line of brush foraging on just about anything it could fit in its mouth.

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The Texas Tortoise occurs in southern Texas and northeastern Mexico.  Here it can be found in a variety of habitats including desert scrub, Tamaulipan Thornscrub, and subtropical forests, grasslands and scrublands.  They feed on a variety of foods, though seem to prefer soft vegetative matter.  They are famous for gorging themselves on prickly pears.  Though they remain common in many areas, they are listed as Threatened by the State of Texas and are protected accordingly.  They face threats from habitat loss and collection for the pet trade.

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We spent close to an hour watching the antics of our states only “true” tortoise.  Armed with super telephoto lenses, we were able to observe the ancient reptile from a distance, and its behavior didn’t seem altered by our presence.  At one point it managed to get a large branch stuck on its gular projection, and spent several minutes dragging it along until it finally was able to free itself.  It then continued foraging until finally disappearing into dense grass under a canopy of mesquite.  This special encounter was the perfect ending to an incredible trip with great company.

The Biodiversity of the Rio Grande Valley Part 3: Las Estrellas del Sur

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It was of the utmost importance that we keep our eyes firmly fixed on the ground – scanning among the stones and parched earth.  Important, because we were in the realm of the Star Cactus (Astrophytum asterias), a very rare, Federally Endangered cactus of the Tamaulipan Thornscrub.  The plants themselves are often flush with the ground, look like little more than some stone or anomaly in the soil.  Their flowers, however, announce their presence to the world in spectacular fashion.  Carolina and I had looked for the Star Cactus in 2017 during a trip with my family.  While we found several plants, we did not have the good fortune to find them in bloom.  This year, however, would be different.

This year we were visiting with our good friends James and Erin Childress.  Having developed a search image during our previous trip, I began noticing a few plants scattered about.  My attention was soon diverted, however, when James and I spotted the brilliant magenta blooms of a group of Fitch’s Hedgehog Cactus.  It was in that moment, as we admired a very different cactus, that Carolina called out that she had found one in flower.  Barely able to contain my excitement, I rushed to her.  It soon become evident that we had timed this visit perfectly, as the floor of the Tamaulipan Thornscrub before me was decorated with dozens of bright yellow and orange blooms.

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Though few known populations exist, where it does occur the Star Cactus can be quite abundant.  Today most of the state’s populations are protected and some are thriving.  We would be telling a very different story, however, if it weren’t for The Nature Conservancy in Texas.  Through the acquisition of land and partnerships with private landowners, The Nature Conservancy has ensured that Astrophytum asterias will not disappear from our state’s diverse flora.  In all, the Nature Conservancy through their Las Estrellas Conservation Cooperative has been able to protect over 2,500 acres of Star Cactus habitat, providing safe refuge for thousands of individuals.

Though it is promising, these successes do not mean that the Star Cactus does not still face threats to its existence.  While speaking with Sonia Najera, Grasslands Program Manager of the Nature Conservancy in Texas, she informed me that continued development adjacent to protected land is threatening A. asterias populations that have no protection.  A. asterias is also under threat from poachers who may collect plants for its popularity in cultivation, and for its resemblance to Peyote, which is extensively collected for its psychoactive properties.

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Despite the many threats that they face, I am optimistic for the future of the Star Cactus in Texas, thanks in large part to the Nature Conservancy and dedicated professionals like Sonia.

The day we spent among Las Estrellas in bloom was really the experience of a lifetime.  We observed and photographed so many spectacular plants in bloom that it was nearly impossible trying to narrow them down to decide what to post.  Below is a small selection of favorites from an unforgettable day in the field.

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