Palmer's False Hymenoxys

TEXAS WILDLIFE BORDERLANDS NEWS BORDERLANDS RESEARCH INSTITUTE FOR NATURAL RESOURCE MANAGEMENT Palmer’s False Hymenoxys How a little-known forb in West Texas is providing insight into desert ecology Article by CHRIS JACKSON and BONNIE WARNOCK ecent research investigating forb diversity and and partner of the O2 Ranch. Currently, the population on the abundance on the O2 Ranch in Brewster County O2 Ranch is the only known locality for the United States. This revealed the identification of a little-known forb that small composite is the only representative of its genus, and we are hasR importance to wildlife. Palmer’s false hymenoxys (Plateilema the first to perform a scientific investigation into its ecology. palmeri) is a small, leafy, stemless, native perennial composite Ecologically, the presence of Palmer’s false hymenoxys on the that grows to only about 6–8 inches tall (Fig. 1); similar in O2 Ranch is interesting because of its disjunct distribution. This appearance to a dandelion. Palmer’s false hymenoxys is likely population is separated by some 150 miles from its nearest locality endemic to the Chihuahuan Desert and has been infrequently in Coahuila, Mexico. Populations in Mexico also show similar documented from few localities in Coahuila and Nuevo León, distribution characteristics. Why are these plants separated by Mexico and historically from Brewster County. such distances and so limited in their distribution? Those are a Prior to its rediscovery, Palmer’s false hymenoxys was last couple of our research questions with many potential answers. documented in 1929 by Henry T. Fletcher—a former manager This plant also gained our interest because its presence is Figure 2: Primary habitat of Palmer’s false hymenoxys on the O2 Ranch. The Figure 1: Palmer’s false hymenoxys grows at the base of a burned western “island” of vegetation surrounded by bare soil is known as banded vegetation honey mesquite. The area was previously treated with prescribed fire. patterning, a natural phenomenon that occurs in many desert flats. LYSSY & ECKEL Supplementing FEEDS the Habitat www.lefeeds.com 22 TEXAS WILDLIFE SEPTEMBER 2016 BORDERLANDS NEWS greater risks of extinction through environmental changes, such as global warming and man-made disturbances. However, it’s important to understand how certain species can tolerate, or even thrive on, certain levels of disturbance. Palmer’s false hymenoxys can reproduce by root cuttings and seems to thrive in areas where mesquite grubbing has taken place, indicating that some level of disturbance may be important for the recruitment of this plant. Management implications towards maintaining this population on the O2 Ranch include: communicating our research results to ranch managers regarding environmental factors and processes towards habitat preferences; identifying critical habitat areas; and recommending erosion mitigating techniques within these habitats. We thank the owners of the O2 Ranch, Table 1: Results of forage analysis of Palmer’s false hymenoxys. Analysis performed by the Texas Lykes Bros. Inc, and the O2 Ranch A&M University Soil, Water and Forage Testing Laboratory in College Station. Manager, Homer Mills, for facilitating our research and their continuing primarily limited to a particular soil 13.3-22.3 percent CP and 63.9-73.8 percent commitment to practicing sound range type and specific habitat (Fig. 2). Plants TDN (Table 1). Through photography we management principles and employing restricted to particular soils, or edaphic have yet to capture images of game species ecological restoration treatments on a endemics, are of interest in the plant consuming it; however, we have been able biologically diverse rangeland in the and soil sciences because of their unique to document other consumers important northern Chihuahuan Desert. association with specific edaphic and to desert ecology such as jackrabbits, As a final note, one of the challenges environmental factors. Understanding grasshoppers, harvester ants and desert we have encountered during our attempts these unique associations is important millipedes. to document additional localities in the from a management perspective for As our research continues, we hope to Trans-Pecos is landowner concerns about habitat conservation and preserving answer questions about soil differences possibly documenting any rare, threatened habitat diversity which leads to resilience. of habitat and non-habitat sites through or endangered plant species (i.e., listed From a utilitarian standpoint, Palmer’s laboratory analysis. Further research is species). However, many landowners aren’t false hymenoxys is interesting because it needed using fecal analysis or additional aware that no federal or state regulatory is foraged regularly. Its low-growing habit cameras to document use of Palmer’s false agency has management jurisdiction over makes it an unlikely candidate for cattle hymenoxys by game species such as mule listed plant species that are rooted on one’s forage so it is most likely being consumed deer and pronghorn. property. If a landowner has a population by wildlife. We sent samples to the Texas We are also using Geographical of listed plant species on their property, A&M Soil & Forage Testing Laboratory for Information Systems (GIS) to potentially no agency can come in and dictate how nutritional analysis and set up a number of predict where else this plant might occur that property is managed. Agencies only motion-activated and time-lapse cameras in the Trans-Pecos portion of Texas have jurisdiction over “commerce” of listed to see if we could capture herbivory in and attempt to gain an understanding species; in other words, if one wishes action. of its disjunct distribution. Tentatively, to dig up and sell a listed plant species, Laboratory analysis revealed that it is because populations are separated by agencies require that one has a permit. very high in crude protein (CP) and total such distances and seeds of Palmer’s false This policy differs from policies regulating digestible nutrients (TDN) making it an hymenoxys are not distributed by wind, wildlife because wildlife species are mobile excellent forage choice. Results show that we think it is unlikely it is distributed by and plants are not. We feel that landowners these percentages are similar to those of organisms and may possibly be a relict should take pride in rare plants as this alfalfa. Alfalfa possesses generally 14-22 species from an earlier and wetter time is a sign that management is helping to percent CP and 54-74 percent TDN, as period. preserve and protect these species. compared to Palmer’s false hymenoxys at Endemic and relict species possess WWW.TEXAS-WILDLIFE.ORG 23.

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