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Shinners & Mahler's Illustrated Flora of North Central Texas

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... Scabiosa atropurpurea L., is an herbaceous plant in the family Dipsacaceae that has become naturalized in northcentral Texas. This species, native to the Mediterranean region (Marques et al., 2007), is rapidly expanding its distribution, particularly along roadsides across the region (Diggs et al., 1999). Scabiosa atropurpurea has the potential to invade pasture and crop land, residential and commercial landscaping, and globally imperiled native tallgrass prairie communities. ...
... In Texas, S. atropurpurea has no known herbivores, parasites, or pathogens. Furthermore, this species has an extended bloom time in Texas, from late May to September (Diggs et al., 1999), and has the potential to produce significantly more seeds than many competitors. Scabiosa atropurpurea is a biennial plant that forms a dense basal rosette in its first year and tall, slender flowering stalks in its second year (Diggs et al., 1999). ...
... Furthermore, this species has an extended bloom time in Texas, from late May to September (Diggs et al., 1999), and has the potential to produce significantly more seeds than many competitors. Scabiosa atropurpurea is a biennial plant that forms a dense basal rosette in its first year and tall, slender flowering stalks in its second year (Diggs et al., 1999). The seeds germinate in close proximity to the mother plant, and, as a result, S. atropurpurea forms dense and closely spaced populations. ...
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Scabiosa atropurpurea is an invasive herbaceous plant now found in 9 states, including 19 counties in north-central Texas and 2 counties in adjacent Oklahoma. Scabiosa atropurpurea forms dense colonies along roadsides and in old agricultural fields and poses a threat to native and improved grasslands. We evaluated the response of S. atropurpurea to mowing and prescribed fire. Mowing caused a marked increase in the density of S. atropurpurea. However, S. atropurpurea declined when there was no management at all and when exposed to growing season fire. Mowing of S. atropurpurea during roadside management and other management contexts leads to persistence and spread of this species. In complex communities, this plant will likely decline and growing season fires may help accelerate these declines.
... The study was conducted in the Cross Timbers and Prairies ecoregion of North Central Texas (Hatch et al., 1990;Diggs et al., 1999) near Lewisville,Texas (Lat. 33.059 N,. ...
... The study site is within the Blackland Prairie Vegetation Area (Diggs et al., 1999), and historically would have supported a Little bluestem-Indiangrass plant community (Diamond et al., 1987;Diamond andSmeins, 1985, 1993). Additionally, this plant community included big bluestem, sideoats grama (Bouteloua curtipendula), tall dropseed (Sporobolus compositus), Texas cupgrass (Eriochloa sericea), and Texas winter grass (Nassella leucotricha). ...
... The introduced plants are often monoculture fields of exotic species that include Bermuda grass (Cynodon dactylon), Johnson grass (Sorghum halepense), King ranch bluestem (Bothriocloa ischaemum), perennial ryegrass (Lolium perenne), and tall fescue (Festuca arundinacea). The remaining acreage is mostly degraded ecologically due to changed frequency, intensity, extent, and magnitude of grazing and lack of periodic managed fire (Diggs et al., 1999). Most high-quality native prairie communities remaining in north central Texas are harvested annually or semiannually as hay meadows . ...
Article
We examined if reintroduction of grazing with or without burning would enhance succession towards native prairie vegetation on previously over-seeded old-field tallgrass prairie subjected to mowing or burning. We hypothesized that returning grazing and fire to these seeded and old-field sites would change establishment and competitive relationships among plant species to benefit fire-tolerant prairie species. Grazing and burning had neutral effects on native prairie species on the previously seeded and unseeded sites over a study period that experienced 70 % of normal precipitation. Herbaceous group categories included old-field grasses, seeded tallgrasses, other grasses (< 2%), seeded perennial forbs, other perennial forbs, and annual forbs. Seeded species comprised about 70 % of the community on seeded plots and 10 % on unseeded plots for the eight years of this study. Seeded-ungrazed tallgrass biomass increased 19 % and on seeded-unburned sites biomass increased 11 %. Tallgrass biomass of unseeded-grazed burned treatment remained at about 4% throughout the study, but with no grazing or no burning biomass, doubled. Changes in biomass associated with treatments led to changes in soil temperatures near the soil surface in summer months. Community dissimilarity was most affected by seeding followed by year, grazing, and burning (P’s = 0.001). Collectively, seeded or unseeded, grazed, or ungrazed site soil temperatures averaged 4.8 °C higher than tree-shaded sites in afternoons of hotter months. Soil temperature differences were inversely proportional to successful site restoration. During afternoons of hotter months, soil temperatures of seeded sites were 1.1 °C lower than unseeded sites, while grazed sites were 2.0 °C greater than ungrazed sites, and burned sites were 1.6 °C higher the year of the burn than unburned sites (P’s < 0.05). While grazing and burning had neutral effects on previously seeded and unseeded prairie sites, seeding accounted for about 70 % of the community on seeded plots and 10 % on unseeded plots.
... The study was conducted in the Cross Timbers and Prairies (Hatch, Gandhi, and Brown 1990;Diggs, Lipscomb, and O'Kennon 1999) ecoregion of North Central Texas near Lewisville, Texas (33 2 0 18 00 N 97 0 0 22 00 W). The climate is continental averaging 220 frost-free growing days. ...
... Neither had it shown any significant natural recovery toward high seral prairie vegetation as had been recorded in other studies with no disturbance management and with no implementation of grazing (Kinucan and Smeins 1992). The site was located within the Blackland Prairie Vegetation Area (Diggs, Lipscomb, and O'Kennon 1999). The study site was a portion of a buffer area in close proximity to the Lake Lewisville dam and subjected to some dam construction activities. ...
... Historically, the site would have supported S. scoparium-S. nutans plant community association (Diamond, Riskind, and Orzell 1987;Diamond and Smeins 1993;Diggs, Lipscomb, and O'Kennon 1999). Subordinate species within this plant association were A. gerardii, Bouteloua curtipendula (sideoats grama), Sporobolus compositus, Eriochloa sericea (Texas cupgrass), and N. leucotricha (Diamond and Smeins 1993). ...
Article
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This study compares degraded old-field grass-dominated pasture response to over-seeding with native tallgrass prairie species with the management practices of burning, mowing and a no-treatment control. Treatments were randomly allocated in a 2 × 3 factorial design with at least six replicate 40 m × 40 m plots. In the third year after treatment species richness increased for seeded vs. unseeded plots (18.9 vs. 14.4 species per plot; p < 0.01) and for mowed or control vs. burned plots (17.4 vs. 15.2 species per plot; p < 0.05). Also, tiller densities of planted tallgrasses increased somewhat to 12% of old-field grass tiller densities (p = 0.001). Multivariate analysis (ANOSIM) the third season following planting indicated some dissimilarity between seeded and unseeded plots (R = 0.32; p = 0.002). After 9 years dissimilarity between seeded and unseeded communities had increased (R = 0.83; p = 0.001) but species richness was similar (p > 0.27). Seeded tallgrasses comprised 44% biomass in seeded vs. 3% in unseeded plots, while seeded forbs comprised 16% biomass in seeded vs. 4% in unseeded plots (p < 0.01). Multivariate analysis of seeded-burned and seeded-mowed sites indicated some dissimilarity (R = 0.25; p = 0.002) with tallgrass biomass being 55% greater (p = 0.001) on mowed sites than controls and 117% greater than burned sites. Tallgrass prairie species planting success may be enhanced with well-timed mowing but harmed by burning when plants are young.
... The study was conducted in the Fort Worth Prairie region, located in Cooke county south of Muenster, North Central Texas, USA (33.6518°N, 97.3764°W). As per Diggs et al. (1999), the climate is continental with an average frost-free growing days and mean annual temperature of 18°C. Mean annual precipitation is 820 mm with a bimodal distribution peaking in May-June and September. ...
... The uplands and midslopes make up the major portion of the landscape and are dominated by the original native vegetation as they are too shallow for agriculture and generally have not been previously tilled. Consequently, they are still used primarily for livestock grazing and recreational hunting (Diggs et al., 1999). On the experimental sites the vegetation was native tallgrass prairie that had not previously been tilled or fertilized. ...
... Native tall prairie grasses dominated the upland and midslope catenal positions and are comprised of tallgrasses Schizachyrium scoparius, Andropogon gerardii, Sorghastrum nutans, Panicum virgatum and midgrasses Bouteloua curtipendula and Sporobolus compositus in association with the perennial forbs Ambrosia psilostachya, Aster ericoides and Gutierrezia texana. Heavy, continuous grazing pressure has resulted in a switch to the grasses Buchloe dactyloides, Bothriochloa laguroides, Bouteloua hirsuta, Nassella leucotricha and annual forbs, particularly Gutierrezia dracunculoides, are more common (Dyksterhuis, 1946(Dyksterhuis, , 1948Diggs et al., 1999). ...
Article
Adaptive multi-paddock (AMP) grazing has demonstrated the potential to substantially improve ecosystems service outcomes relative to the most commonly used grazing management of moderate (MC) and heavy continuous (HC) grazing. We hypothesize that AMP grazing would decrease net soil emissions of CO2, CH4 and N2O exchange between the soil surface and the atmosphere relative to continuous grazing and the management practice options of prescribed fire (AMP-burn), and production of hay (AMP-hay) both managed using AMP grazing. Soil temperature was lower (P < 0.009) and soil moisture higher (P < 0.01) with AMP grazing than with HC and MC grazing. As CO2, CH4 and N2O emissions are less with lower temperatures and increasing soil moisture, they should have declined with AMP grazing. However, AMP grazing had the highest and HC the lowest CO2 emissions, indicating higher levels of soil respiration, an index of soil microbial activity, with AMP. Emissions of N2O were consistent with previous research, being higher under anaerobic conditions and very low under aerobic conditions. AMP, AMP-burn and AMP-hay treatments on average had lower N2O emissions than HC and MC (P ≤ 0.002). Methane (CH4) emissions were negative for most sample dates but were dwarfed by the occasional periods when soils were saturated. These elevations in CH4 emissions occurred on 8 of the 35 dates sampled (rate >0; P ≤ 0.05), 7 times for HC, 4 times for MC, and 3 times for AMP. On the remaining dates sampled (27 of 35), AMP was the strongest CH4 sink ahead of AMP-burn (P = 0.0335), AMP-hay (P = 0.0232) and HC, but was similar to MC (P = 0.17). MC was a stronger sink than HC (P = 0.057). The emissions of CO2 and N2O were decreased with removal of green canopy material at sampling, indicating positive responses could be achieved by adjusting grazing management. Adaptive multi-paddock grazing, but not continuous grazing, can be adjusted to maintain higher proportions of green material, and as this would also benefit energy capture by photosynthesis and livestock diet quality, multiple benefits could accrue from implementing such management. Removal of green material had no influence on CH4 oxidation, which was greatest with AMP grazing. These results are consistent with AMP grazing having a lower intensity ecological impact than continuous grazing.
... All major plant communities and habitats occurring at Hunewell Ranch were sampled. Specimens were processed at TSU Herbarium using standard herbarium procedures (Diggs et al. 1999). Each specimen from Hunewell Ranch was identified and classified as native, endemic, or introduced using Shinner's and Mahler's Illustrated Flora of North Central Texas (Diggs et al. 1999). ...
... Specimens were processed at TSU Herbarium using standard herbarium procedures (Diggs et al. 1999). Each specimen from Hunewell Ranch was identified and classified as native, endemic, or introduced using Shinner's and Mahler's Illustrated Flora of North Central Texas (Diggs et al. 1999). Plants from Hunewell Ranch will be compared to those which occur on the Texas State-listed Noxious Weeds (USDA 2016), state threatened and endangered plant species list (TPWD 2016), and rare plants of Texas (Poole et al. 2007). ...
... Asclepias verticillata L. (Whorled milkweed; TAC 4480), a native milkweed, occurs in nearby Parker County in sandy open woods, rocky slopes, and prairies (Diggs et al. 1999;Turner et al. 2003a). Its collection at Hunewell Ranch extends its range further west in the WCT. ...
Article
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Data from floras are critical in establishing species' ranges. This knowledge is essential to conserving plant species and monitoring the spread of introduced species. New plant records in Erath County as well as information on the number of native, endemic, introduced and rare species are reported for plants at Tarleton State University's Hunewell Ranch. Species are compared to those occurring on the state noxious weeds and threatened or endangered species lists. Plant specimens were. Eighty-eight taxa were new to Erath County and 43 of these are major range extensions of plants into the West Cross Timbers. None of the specimens encountered during the study were found to be on the state noxious weeds list, were considered rare, nor were any threatened and endangered species discovered at Hunewell Ranch.
... Grasslands in the southern Great Plains are generally dominated by C 4 species such as big bluestem (Andropogon gerardii Vitman), Indian grass (Sorghastrum nutans [L.] Nash), little bluestem (Schizachyrium scoparium [Nash] E.P. Bicknell), and various grama species (Bouteloua spp.; Diggs et al., 1999). Many of the common non-natives in the region are also C 4 grasses; these include crowngrasses (Paspalum spp.), lovegrasses (Eragrostis spp.), ...
... Yellow bluestem is most vulnerable to fire during stem elongation, when plants begin to form flowering stems, but before they actually flower (Ruckman et al., 2012b;Havill et al., 2015). Yellow bluestem flowers throughout the growing season (approximately April-November), with flowering often triggered by rainfall (Diggs et al., 1999;Ruckman et al., 2012b). In this region, early fall rains often trigger a pulse of flowering after typically dry summers. ...
... Yellow bluestem has previously been shown to be most vulnerable to fire when fewer than half of the culms were reproductive (Ruckman et al., 2012b). Yellow bluestem can flower year-round, depending on rainfall, but most seed production occurs during spring and fall (Coyne and Bradford, 1985;Diggs et al., 1999), suggesting that fall burns would often target the species during a vulnerable period. ...
Article
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Yellow bluestem (Bothriochloa ischaemum [L.] Keng var. songarica [Rupr. ex Fisch & C.A. Mey] Celarier & Harlan) is a non-native, invasive C4 grass common in southern Great Plains rangelands. We measured the effects of a single late-summer (September 2006) fire on yellow bluestem at two sites in central Texas (Fort Hood and Onion Creek). At Fort Hood, relative frequency of yellow bluestem in burned plots decreased from 74 ± 4% (pre-burn; mean ± standard error) to 9 ± 2% (2007) and remained significantly lower compared to unburned plots through 2009 (burned: 14 ± 2%; unburned: 70 ± 14%). At Onion Creek, yellow bluestem initially decreased from 74 ± 5% (2006) to 32 ± 7% (2007). Yellow bluestem recovered substantially by 2009 (67 ± 10%) but was still significantly lower than in unburned transects (96 ± 1%). Relative frequency of other graminoids increased significantly in burned plots (compared to pre-burn values) at Fort Hood (pre-burn: 11 ± 4%; 2009: 29 ± 7%), but not at Onion Creek (pre-burn: 24 ± 6%; 2009: 22 ± 7%). Frequency of forbs increased dramatically in the first growing season after fire (Fort Hood: 15 ± 2% to 76 ± 3%; Onion Creek: 2 ± 2% to 45 ± 5%), then decreased through the third growing season (Fort Hood: 57 ± 6%; Onion Creek: 11 ± 4%). Key differences between the sites include much higher biomass at Fort Hood than at Onion Creek (8130 kg ha-1 vs. 2873 kg ha-1), more recent grazing at Onion Creek (ending in 2000 vs. before 1996 at Fort Hood), and higher rainfall after the Onion Creek burn (214 mm in 20 days vs. 14 mm). Late-summer fire can temporarily decrease yellow bluestem frequency, but effects vary with site conditions and precipitation. Restoring dominance by native grasses may require additional management.
... Plant species that could not be readily identified in the field were collected and identified using Shinner's and Mahler's Illustrated Flora of North Central Texas (Diggs et al. 1999 Representative site photos were taken at each plot center facing due north. Data regarding location information (latitude/longitude), soils, soil texture, aspect, and hydrology were also recorded for each sample location. ...
... Indian paintbrush (Castilleja indivisa), Texas star (Sabatia campestris), and Texas wintergrass (Nasella leucotricha) dominated the area. Texas wintergrass was originally a minor component of most prairies but is now much more common due to disturbance ( Figure 10. ) (Diggs et al. 1999). ...
... ), Arkansas yucca (Yucca arkansana), green antelopehorn, tulip prickly-pear (Opuntia phaeacantha), and Texas star. Engelmann's daisy (Engelmannia peristenia) occurred here which is often said to be an "ice-cream plant" preferentially grazed by cattle, resulting in its absence from the landscape under typical grazing regimes (Diggs et al. 1999). Figure 19. ...
Technical Report
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This study surveyed and mapped the plant communities at Lake Aquilla, Hill County, Texas. The condition of the communities and their potential for future applications of selected restorative practices were also evaluated. Emphasis was placed on locating potential Texas Blackland prairie remnants, shrublands that may support the federally threatened Black-capped vireo (Vireo atricapilla Woodhouse), and oak-juniper woodlands that may support the federally endangered Golden-cheeked Warbler (Dendroica chrysoparia P. L. Sclater and Salvin). Data was collected using a combination of plots and transects. All vascular plant species were recorded, as well as their abundance and growth form. Plant community classifications were adapted from those developed by the National Vegetation Classification System for the state of Texas. Two-hundred and twenty-seven species of vascular plants were recorded from 27 sample locations. Remnant patches of Texas Blackland prairie degraded by fire suppression and previous land use practices were identified in the survey area. Shrublands suitable for the black-capped vireo, and oak-juniper woodlands suitable for the golden-cheeked warbler were not detected in the survey area. Restorative practices that include management of undesirable woody vegetation and application of prescribed fire were recommended for the grasslands, and oak woodlands and forests at Lake Aquilla.
... Зрели плодове, (Minnick et. Al., 1987;Diggs et.al., 1999) Кора, дървесина (Minnick et аl., 1987;Diggs et al., 1999) - ...
... Table 5. Continued. Melia azedarach L. Ozturk et al., 2008Ozturk et al., 2008Hedrick, 1972Grieve, 1984;Polunin, Huxley,1987;Duke, Ayensu, 1985;Diggs et al., 1999;Ozturk et al., 2008 -[7] ВНИ-МАНИЕ токси- Diggs et al., 1999;Johnson, Johnson, 2006;NGIA, 2007;(4) Mespilus germanica L. ...
... Table 5. Continued. Melia azedarach L. Ozturk et al., 2008Ozturk et al., 2008Hedrick, 1972Grieve, 1984;Polunin, Huxley,1987;Duke, Ayensu, 1985;Diggs et al., 1999;Ozturk et al., 2008 -[7] ВНИ-МАНИЕ токси- Diggs et al., 1999;Johnson, Johnson, 2006;NGIA, 2007;(4) Mespilus germanica L. ...
Article
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TOXIC WOODY ORNAMENTALS IN THE LANDSCAPE DESIGN I. TREES. This review outlines the risk posed by toxic ornamental plants, as well as points out a solution for avoiding the problem according to other countries. Poison Information Centres data indicates that there are many poisoning incidents and small children are the ones mostly affected. A considerable number of toxic tree species are available on sale in plant nurseries and garden centres. The first step towards highlighting the problem was to compile a list of toxic ornamental trees, their toxic parts and toxic rate. According to the practice of UK and Australia a low-cost solution to the toxic plant threat is developing and implementing a national code for labeling of toxic species.
... Plants were collected in the vicinity of Garland Bend in riparian habitat adjacent to the river or in riverine marshes. Specimens were processed at TSU Herbarium (TAC) using standard herbarium procedures (Diggs et al. 1999). Each specimen was identified and classified as native, endemic, or introduced using Shinners and Mahler's Illustrated Flora of North Central Texas (Diggs et al. 1999). ...
... Specimens were processed at TSU Herbarium (TAC) using standard herbarium procedures (Diggs et al. 1999). Each specimen was identified and classified as native, endemic, or introduced using Shinners and Mahler's Illustrated Flora of North Central Texas (Diggs et al. 1999). Plants were compared to those listed on the Texas State-listed Noxious Weeds (USDA 2010), state and federal threatened and endangered plant species list (TPWD 2010), and rare plants of Texas (Poole et al. 2007). ...
... PONTEDERIACEAE Heteranthera dubia (Jacq.) MacMill (Water star-grass; TAC 4376-4378) is a native, aquatic herb found in small streams and quiet waters (Diggs et al. 1999). The closest location where the plant has been collected is Dallas County to the east with a number of collection localities in counties bordering the Colorado River to the west (Turner et al. 2003b). ...
... Senecio vulgaris L. (common groundsel; TAC 4138) is a groundsel introduced from Europe ( Diggs et al. 1999). It has been reported from Brown County in the west and Tarrant and McLennan counties to the east (Turner et al. 2003a). ...
... O.E. Schulz (rocketweed; TAC 4099) is an introduced mustard from Europe (Diggs et al. 1999). Its collection in Somervell County represents a westward range extension from Hill and Tarrant counties from the southeast and northeast, respectively (Turner et al. 2003a). ...
... Floral records for Somervell County that have also been reported from bordering counties (Turner et al. 2003a;2003b) including Bosque (B), Erath (E), Hood (H), and Johnson (J). Sisymbrium irio L. (rocket-mustard; TAC 4140), an introduced European mustard (Diggs et al. 1999), is known from Comanche and Dallas counties (Turner et al. 2003a). Its collection in Somervell County fills in a distribution gap between the two counties. ...
Article
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Scutellaria drummondii var. edwardsiana (Drummond's skullcap) and S. wrightii (Wright's skullcap) use hydroballochory to disperse nutlets following rains. The nutlets form in a fruiting calyx called a scutellum that expands in size and changes in color from green to yellow and finally brown. The scutellum has a cup-shaped upper portion and a scale-like lower portion. When a drop of rain hits the cup-shaped top of a yellow or brown scutellum, it dehisces and falls off the plant and the resulting mechanical energy from this event causes the scales to throw the nutlets away from the plant. Based on field and greenhouse experiments scutella were observed to disperse following precipitation events.
... In fact, the tone of a few of the articles and discussions (on both sides of the argument) has been surprisingly impolite by the standards of modern scientific discourse, with Webster (2002) referring to the arguments as "an ideological cacophony of bombast and invective." There is a voluminous literature on the subject, including numerous recent articles about the different taxonomic and nomenclatural approaches (e.g., Moore 1998; Stevens 1998;Diggs et al. 1999 ( Forey 2002;Kress & DePriest 2002;Nicolson 2002;Webster 2002). Symposia and workshops have also been held (XVI International Botanical Congress-August 1999; Smithsonian's National Museum of Natural History-March 2001; Hunt Institute for Botanical Documentation-June 2002), and a new system of nomenclature has been proposed ( PhyloCode 2002). ...
... According to Sanders and Judd (2000), these are: 1) to provide entry into the systematic literature; 2) to provide thumbnail summaries of the current state of our knowledge (including systematic, ecological, ethnobotanical, etc.); 3) to serve as a reference for other professionals; and 4) to fix the concepts of taxa, especially families and genera, in the minds of users. Generally we agree with these secondary goals, and expended considerable thought and effort in applying them in our previous floristic effort ( Diggs et al. 1999). We also agree with Sanders and Judd (2000) that there is a critical need for the collaboration (and probably more importantly cross-training) of floristic, monographic, and phylogenetic researchers. ...
... In a draft family synopsis we ( Diggs et al. in prep.) say, In the past, taxa included here in the Nolinaceae were sometimes included in a broadly conceived Liliaceae (e.g., Kartez 1999) or often in the Agavaceae (e.g., Correll & Johnston 1970;Diggs et al. 1999;Verhoek & Hess 2002following Cronquist 1988) based on certain morphological similarities. However, recent evidence suggests that the Agavaceae and Nolinaceae are not closely related and should be recognized separately ( Dahlgren et al. 1985;Eguiarte et al. 1994;Bogler & Simpson 1995Kubitzki et al. 1998;Chase et al. 2000). ...
Article
Plant classification and nomenclature are in a continuing state of flux and heated debate between two opposing schools - 1) traditional taxonomists supporting "evolutionary" or "Linnaean taxonomy"; and 2) cladists supporting "phylogenetic systematics" or "cladonomy." While it is a multifaceted controversy that has spanned several decades, relatively little attention has been focused specifically on the ramifications for floristics. The two goals of this paper are 1) to give special emphasis to the implications of the controversy for the writers of floras, and 2) to provide an overview of some of the arguments in a format accessible to a diverse audience of botanists interested in floristics. We examine some of the issues we have confronted in our floristic work, discuss how we are attempting to balance the strengths and weaknesses of both approaches, and indicate what we believe is the best, albeit imperfect, approach to the writing of floras at the present time. We argue that, for both practical and theoretical reasons, a modified traditional system (binomial nomenclature, ranked hierarchies) be used in floras (allowing paraphyletic groups but eliminating all polyphyletic groups despite some nomenclatural instability). Further, these floras should incorporate information on newly discovered phylogenetic relationships (even if too preliminary, tentative, or inappropriate for nomenclatural change) and discuss these in appropriate family and generic treatments in order to facilitate as complete an understanding of plant evolution as possible.
... Selected wildflower species for this study were Gaura villosa (gaura), Xanthisma texanum (sleepy daisy), and Ipomopsis rubra (standing cypress) (Fig. 1). Each species is native to North America, requires partial shade to full sun, thrives in sandy to gravely poor soils, and is thought to exhibit potential as an ornamental landscape species (Diggs et al., 1999;U.S. Department of Agriculture, 2018;Wasowski and Wasowski, 2000). ...
... However, shoot dry weight of G. villosa did not differ across salinity treatments, although a progressive decline in shoot mass of G. villosa was clearly seen as salinity levels increased (Fig. 7C). In addition, there were no differences in the shoot dry weight of I. rubra among salinity treatments (Fig. 7C), which could be explained by I. rubra's compact rosette growth habit (Diggs et al., 1999). A reduction in shoot dry weight is one of the typical symptoms of osmotic stress caused by elevated salinity levels (Montesano and Van Iersel, 2007;Wang et al., 2019). ...
Article
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Water quality and quantity are critical issues in the Southwest United States and many other locations in the world. Use of reclaimed water for landscape irrigation can conserve potable water significantly and possibly reduce fertilizer application. A potential concern of using alternative water sources is elevated salt levels, which can have adverse effects on plant growth and aesthetic appearance. Most Texas native wildflowers are known to be hardy and easy to maintain, and are drought tolerant after establishment. In addition, native wildflowers provide wildlife habitat and support native pollinators. However, little information is available on salinity tolerance of many Texas native wildflower species. In this study, two separate hydroponic experiments were conducted to determine salt tolerance of three Texas native wildflower species: Gaura villosa Torr. (wooly gaura), Xanthisma texanum DC. (Texas sleepy daisy), and Ipomopsis rubra (L.) Wherry (standing cypress). Species were suspended in a hydroponic setting using a randomized complete block design with a control [municipal reverse-osmosis (RO) water with a nutrition solution at an electrical conductivity (EC) of 3.0 dS·m –1 ] and three salinity treatments: 5.0, 7.0, and 11.0 dS·m –1 EC. Sixty days after salinity treatments were initiated, percent survival, visual rating, fresh weight, and length measurements were recorded on root and shoot tissue. To determine tissue percentage sodium (Na ⁺ ), calcium (Ca ²⁺ ), and chloride (Cl – ), shoot and root tissues were dried and ground for tissue analysis. At the end of each experiment, total percent survival for X. texanum, G. villosa , and I. rubra were 100%, 94%, and 76%, respectively, with the greatest mortality rate at the highest salinity treatment. Shoot dry weight and plant growth index (PGI) decreased in all three species as salinity of irrigation water increased. Visual qualities of all species were mainly compromised at the highest salinity level. Ion concentrations in root and shoot tissues were affected by salinity levels and varied among species. Different mechanisms of salt tolerance (ion exclusion, salt excretion, and tissue tolerance to high concentrations of Na ⁺ or Cl – ) have been observed among wildflower species, and results indicate different salt tolerance mechanisms were exhibited by each trial species. In addition, results indicate I. rubra can be identified as moderately salt tolerant (EC up to 7.0 dS·m –1 ), whereas, X. texanum and G. villosa can be classified as salt tolerant (EC up to 11.0 dS·m –1 ). Results from this study suggest great potential of these native Texas wildflowers in landscapes using limited-quality irrigation water or landscapes with soil salinity concerns.
... Plant species that could not be readily identified in the field were collected and identified using Shinner's & Mahler's Illustrated Flora of North Central Texas (Diggs, et al., 1999). Due to nomenclatural changes that have been made since its publication, the survey applied the currently accepted name found in Flora of North America (http://floranorthamerica.org/), and Integrated Taxonomic Information System (http://www.itis.gov). ...
... Limestone outcrops embedded within mesic forests below the dam contained a small population (approximately eight plants) of rough lipfern (Cheilanthes horridula; Figure 13). This fern is typically associated with limestone, and mostly found in the western 2/3 rds of TX (Diggs, et al., 1999). ...
Research
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The purpose of this survey was to conduct a botanical inventory and generate a map of vegetation types found on project lands owned and operated by the US Army Corps of Engineers (USACE) - Fort Worth District at Proctor Lake, Texas (TX). This report is intended to provide support for ongoing and future management decisions, and identify opportunities for habitat restoration. While conducting the survey, emphasis was placed on locating remnant patches of grasslands, oak woodlands, and glade communities. This survey is not intended to provide a comprehensive flora, and therefore does not describe or account for every plant species that occurs at Proctor Lake. Comprehensive floras, while valuable, require substantial inputs of time and effort in locating and identifying as many species as possible, making other mission objectives secondary in nature, which does not meet the project objectives outlined above.
... Native and exotic species were selected using a paired species approach that controlled for phylogeny and growth form between pairs of native and exotic species. We used a large pool of native and exotic species; all exotic species used were already present in the Texas flora (Diggs et al. 1999). The species composition of our plots (mixtures) was very similar to species composition of fields in the area, and our study used all of the non-native species in the area (Wilsey et al. 2011) that could be paired with native species. ...
... Experimental response variables were analyzed using a mixed-model ANOVA with PROC MIXED in SAS 9.2 (SAS Institute, Cary, North Carolina, USA) with grassland origin (native vs. exotic), irrigation, and block as fixed factors, and species composition (draw [block]) and its interactions as random factors (Wilsey et al. 2011), using the Kenwood-Roger correction method. We used repeated-measures ANOVA with a firstorder autoregressive (1) covariance structure to analyze responses of RUE, species richness, Simpson's diversity, biomass of different functional groups-C 3 grasses, C 3 forbs, C 3 legumes, C 4 grasses, and short (<45 cm) grasses (overlapped with the C 3 and C 4 grasses)-to drought (Diggs et al. 1999). Plant functional groups were used in analyses rather than individual species because all of the species were not included in all mixtures. ...
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Extreme droughts can have profound direct consequences for grassland ecosystems, but it is poorly known how ecosystems recover from drought and what ecological factors are associated with recovery. Recovery occurs when ecosystem functioning returns to values observed prior to a perturbation. Here, we tested for ecosystem recovery after an extreme drought in 2011 in previously established native and exotic experimental communities in Central Texas. Planted mixtures of all native and all exotic species were crossed with a summer irrigation treatment, with eight community compositions (random draws) per treatment. Prior to the drought, native plots had higher diversity than exotic plots, which sets up the prediction that the high-diversity native plots will recover more quickly than exotics. The extreme drought decreased rain-use efficiency ([RUE], annual biomass production per unit of rainfall) by 82%. Rain-use efficiency remained well below pre-drought levels during the growing season after the drought. However, on average, RUE recovered to pre-drought levels by the second growing season following drought. Exotic communities showed higher RUE than native communities, and irrigation significantly reduced RUE in both exotic and native communities across years. Interestingly, not all of the mixtures recovered from the drought, and recovery was associated with species composition, but not diversity. Rain-use efficiency recovery from drought was greatest in native communities in which the proportion of C3 forb biomass increased during and following drought and in exotic communities with a low proportion of short grass biomass. Extreme droughts can exert differential impacts on plant functional groups, leading to a drought legacy effect that reduces recovery with possible long-term repercussions.
... A primary benefit of native germplasm is that it often requires less input (Phillips and Coleman, 1994) and is more likely to persist because of local adaptation to soils, climates, pests, and competing vegetation. In the southern Great Plains of North America, native perennial bunchgrasses such as yellow Indiangrass, switchgrass, and little bluestem are widely adapted (Diggs et al., 1999) as well as, in the case of switchgrass, capable of average yields near 15 Mg ha −1 y −1 depending on rainfall and fertilizer application (Muir et al., 2001Kiniry et al., 2005). In drier climates, they pose less of an invasive weed threat than do some introduced bunchgrasses such as buffelgrass [Pennisetum ciliare (L.) Link; Buyuktahtakin et al., 2014], old world bluestem [Bothriochloa bladhii (Retz) S.T. Blake] (Harmoney et al., 2010), or Bothriochloa ischaemum (L.) Keng var. ...
... The question is whether the difficulty associated with establishing perennial, warm-season bunchgrasses is compounded by simultaneously seeding with annual warm-season legumes. Most research to date on North American grass and legume combinations has focused on binary perennial forage systems where grass and legume are harvested simultaneously (Posler et al., 1993); by contrast, North American bunchgrass bioenergy systems experience greatest HY and stand persistence when harvested after winter dormancy when annual warm-season legumes of the southern Great Plains have largely disappeared (Diggs et al., 1999). ...
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Weak seedling vigor of native North American perennial bunchgrasses may result in poor establishment-season herbage dry matter (DM) yields (HY). Interseeding North American annual legumes as an N source during grassland restoration, pasture establishment, or bioenergy crop seeding might compound this limitation. Our first objective was to evaluate yellow Indiangrass [Sorghastrum nutans (L.) Nash], switchgrass (Panicum virgatum L.), and little bluestem [Schizachyrium scoparium (Michx.) Nash] first-season HY in the southern Great Plains of North America. This took place in north–central Texas on a Windthorst fine sandy loam soil with no irrigation or soil amendments. Our second objective was to measure the effects of cross-drilling native North American annual legumes smooth-seeded wild bean [Strophostyles leiosperma (Torr. & Gray) Piper], trailing wild bean [Strophostyles helvula (L.) Elliott], and showy partridge pea [Chamaecrista fasciculata (Michx.) Greene] on bunchgrass first-season HY. In the drier (340 mm) year, legumes failed to establish, while switchgrass produced 2410 and Indiangrass yielded 1980 kg HY ha⁻¹ y⁻¹. In the year with 687 mm rainfall, legumes had no negative effects (P > 0.05) on grass HY (5490 kg HY ha⁻¹ y⁻¹ for switchgrass) despite providing up to 49 through 1800 kg HY ha⁻¹ y⁻¹ (showy partridge-pea with little bluestem; P ≤ 0.05 for year by grass × legume interactions). Our results indicate that these bunchgrasses produced harvestable HY during their establishment year and that simultaneously seeding annual legumes did not impair native perennial grass establishment while, in 1 yr, making potential N contributions for subsequent stand productivity.
... The phyllaries are 3-5 x 1.4 mm. The fruit is a pappus-bearing achene (Diggs Jr. et al. 1999). ...
... The plant is very slender, much branched, rooted, submerged, herbaceous, grass-like, bright green, 10 to 60 cm long; roots may become long, creeping in soft mud [6]. This is one of the few genera of plants where fertilization takes place under the surface of the water [7]. A native of Africa, Middle East, Mediterranean areas, South and Central Asia, Papua and Australia, naturalized in Britain, it is becoming an increasingly invasive plant throughout the world, populating various types of still and slow-moving waters, ponds, paddy fields [8]. ...
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Najas graminea Delile species is a common submerged water plant, becoming more and more widespread in Southeast Europe. The aim of this research was to determine at experimental level, the aluminum bioaccumulation potential of this aquatic plant, found in still or slow-moving freshwater habitats. Najas graminea plants were grown in experimental aquariums conditions, at different Al 2 (SO 4) 3 concentrations. The evolution of water parameters (pH, dissolved oxygen, electrical conductivity, and total dissolved solids) was monitored. Aluminium bioaccumulation was assessed at the end of the experiment, through atomic absorption spectrometry (AAS), and the concentration of photosynthetic pigments and final dry plant biomass were determined by solvent extraction and UV-Vis spectrometry, and respectively, gravimetric method. Aluminium hyperaccumulation in Najas graminea plants (9,309 mg/kg, accumulation coefficient 9.31) occurred only at the highest ambient concentration, of 1,000 mg/kg Al. Background concentrations of 100-1,000 mg/kg induced a significant drop in chlorophylls and carotenoids concentration, however, without a proportional decrease in plant biomass. Also, no significant differences in dissolved oxygen were found. Increases in pH, conductivity and dissolved solids were observed, however they cannot be attributed to Najas graminea plants. Obtained results emphasize that Najas graminea Delile species act as a valuable aluminium bioaccumulator, with possible applications in bioremediation of freshwater quality.
... With the goal of identifying all taxa to the finest taxonomic level, vasuclar plant species lists were generated by meander searches or a plot-based method (for details see Bried et al., 2016Bried et al., , 2019Jog et al., 2017). Most species were identified in the field, while some of the more difficult graminoid taxa were identified in the lab using regional, state, and national keys (Diggs et al., 1999;Flora of North America Editorial Committee, 1993;Tyrl et al., 2009). The same botanist (S.K.J.) led all surveys and identified a cumulative total of 432 species represented by 246 genera and 86 families across all 115 sites. ...
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Biomonitoring typically uses taxonomic diversity information while ignoring phylogenetic diversity. Evolutionary relatedness may offer deeper insight to how local assemblages relate with human disturbance and ecological degradation. Degradation of floristic quality may filter species with similar evolutionary traits, whereas intact floristic quality may limit phylogenetic clumping and increase representation of more distantly related taxa. We tested this hypothesis using average taxonomic distinctness (AvTD) and measures of floristic quality (mean ecological conservatism, native species richness, percent exotic species) in vascular plant assemblages of 115 wetlands in the US southern plains. In line with the hypothesis, we observed positive correlations with conservatism (r = 0.28, P = 0.0007) and native richness (r = 0.24, P = 0.0018) and a negative correlation (r = −0.21, P = 0.0169) with exotics, but the plotted relationships looked obscure. A strongly skewed AvTD distribution revealed a clear gradient in lower than expected AvTD. Responses along this gradient covaried with native richness (quadratic model R² = 0.75) but showed no pattern with conservatism and a weak response to exotics. These results suggest that native richness has potential to predict lower than expected AvTD values. However, attributing these values to degraded floristic quality requires caution when richness is driven by sampling effects such as species-area relationships or has a non-linear relationship to human disturbance. Given the vague correlations and ambiguity of richness, plant taxonomic distinctness may not provide a clear bioindicator for wetlands. More work is needed to elucidate how evolutionary structure may play into bioassessment, which traditionally has been phylogenetically neutral.
... tic that most changes with grazing, with greater legume selection, due to the greater palatability of many of these plants, when compared to grasses. In Texas, USA, rangeland, for example, there are 69 genera of herbaceous and shrub legumes (Correll & Johston, 1970), while in the Cross Timbers Region, covering 3,600 km 2 of that state and Oklahoma , Diggs Jr. et. al. (1999) identified 50 herbaceous legume species. Even after 160 years of overgrazing and fire use, Texas contains over 100 legume species endemic to its native pastures (Turner, 1959), although these have been extirpated in many overgrazed rangelands. ...
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Rangelands and other native pastures occupy a large area of the planet, with greater temporal and spatial botanical composition and productivity variability. Despite the continuous and historical use of these areas, including overgrazing and fire exclusion, endemic legume species persist in some semiarid rangelands. The objective this work was to review current knowledge of legume use, especially those of the Brazilian Caatinga rangeland. Studies that measure the qualitative and quantitative variations of native legumes are essential for ruminant feed supplementation, to the sustainability of animal production, as well as for economic and environmental improvements in rangelands. Caatinga vegetation of northeastern Brazil consists of deciduous shrubs and small trees which mostly lose their leaves at the beginning of the dry season. The legume family contributes to the greatest number of endemic species but little is known about their productivity or nutritive values. Livestock select Orelha de onça [Macroptilium martii (Benth.) Marechal & Baudet] and Mororó (Bauhinia cheilantha (Bong.) Steud.) and these should, during rangeland clearing, be preserved. In addition, although Caatinga legumes have great crude protein content, their biological fixation of atmospheric N has yet to be thoroughly studied. On the negative side, some native Caatinga legumes have great levels of neutral detergent fiber-bound N (NDFN) and condensed tannin. As a result, animal performance in Caatinga is often poor, notably in the dry period. Forage legumes also provide several environmental services such as N input via BNF and rehabilitation of degraded land.
... Disk florets from specimens of Calyptocarpus in Mexico were reported to have either four or five anthers (McVaugh and Smith 1967;McVaugh 1984), and Gibson (2013+) observed both these numbers in Williamson County, Texas. Although the anther number was not listed by the authors in the Illustrated Flora of North Central Texas (Diggs et al. 1999), the illustration by Linny Heagy in the text displayed four anthers. ...
... The roots are rich in starch and can be ground into a powder and used in soups or with cereals for making bread (Yanovsky, 1936). The roots were used an important source of food for the native North American Indians (Diggs et al., 1999). Psoralea macrostachya DC. (Large Leather Root) roots are eaten raw or cooked and may be dried for winter use. ...
Article
Ethnopharmacological relevance: The genus Psoralea (Fabaceae) harbours 105 accepted species that are extensively used by local peoples and medicinal practitioners of China, India, and other countries for treatment of tooth decay, psoriasis, leucoderma, leprosy, kidney problems, tuberculosis, indigestion, constipation and impotence. Presently, pharmacological research reports are available on only few species namely Bituminaria bituminosa (Syn: P. bituminosa), P. canescens, P. corylifolia, P. esculenta, P. plicata and P. glandulosa which are valued for their chemical constituents and traditional uses. Aim of the review: This review article provides explicit information on traditional uses, phytochemistry, and pharmacological activities of selected Psoralea species. The possible trends and perspectives for future research on these plants are also discussed. Materials and methods: An extensive and systematic review of the extant literature was carried out, and the data under various sections were identified using a computerized bibliographic search via the PubMed, Web of Science and Google Scholar, CAB Abstracts, MEDLINE, EMBASE, INMEDPLAN, NATTS as well as several websites. Key findings: A total of 291 bioactive compounds from 06 species of genus Psoralea have been isolated and characterized. However, P. bituminosa alone possess nearly 150 compounds. These bioactive compounds belong to different chemical classes, including flavonoids, coumarins, furanocoumarins, chalcones, quinines, terpenoids and some others due to which these species exhibit significant anti-oxidant, anti-bacterial, anti-fungal, anti-viral, anti-helmintic, anti-diabetic, diuretic, hepatoprotective, anti-cancer and anti-tumor activities. P. corylifolia L. (Babchi), a Chinese traditional medicinal plant has been used in traditional medicine for many decades for its healing properties against numerous skin diseases such as leprosy, psoriasis and leucoderma. Conclusions: The in vitro studies and in vivo models have provided a simple bio-scientific justification for various ethnopharmacological uses of Psoralea species. From the toxicological perspective, the root, leaf, and seed extracts and their preparations have been proven to be safe when consumed in the recommended doses. But, meticulous studies on the pharmaceutical standardization, mode of action of the active constituents, and sustainable conservation of Psoralea species are needed, to meet the growing demands of the pharmaceutical industries, and to fully exploit their preventive and therapeutic potentials.
... Seedlings of seven perennial species, including four C 4 grasses, two C 3 forbs and one herbaceous legume, were transplanted into each monolith 3 yr before CO 2 treatment. All species are native to central Texas (Diggs et al., 1999) and present in the Texas Blackland Prairie. Eventual community dominants included the C 4 grasses Bouteloua curtipendula (Michx.) ...
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Atmospheric CO2 enrichment usually increases aboveground productivity (ANPP) of grassland vegetation, but the magnitude of the ANPP‐CO2 response differs among ecosystems. Soil properties affect ANPP via multiple mechanisms and vary over topographic to geographic gradients, but have received little attention as potential modifiers of the ANPP‐CO2 response. We assessed effects of three soil types, sandy loam, silty clay, and clay, on the ANPP response of perennial C3/C4 grassland communities to a subambient to elevated CO2 gradient over 10 years in Texas, USA. We predicted an interactive, rather than additive, effect of CO2 and soil type on ANPP. Contrary to prediction, CO2 and soil additively influenced grassland ANPP. Increasing CO2 by 250 μL L−1 increased ANPP by 170 g m−2 across soil types. Increased clay content from 10% to 50% among soils reduced ANPP by 50 g m−2. CO2 enrichment increased ANPP via a predominant direct effect accompanied by a smaller indirect effect mediated by successional shift to increased dominance of the C4 tallgrass Sorghastrum nutans. Our results indicate a large, positive influence of CO2 enrichment on grassland productivity that resulted from direct physiological benefits of CO2 augmented by species succession and was expressed similarly across soils of differing physical properties. This article is protected by copyright. All rights reserved.
... The West Gulf Coastal Plain (WGCP) in southwestern Arkansas, western Louisiana, southeastern Oklahoma, and eastern Texas contains the westernmost examples of bottomland hardwood forests. Forests in these regions often exhibit a different character than those more common in the eastern part of the range, largely reflecting differing soils, lower annual rainfall, and different hydrology (Diggs et al., 1999;Bennett, 2013). Of 13 chiropteran species occurring in east Texas, eight are either entirely or partially dependent on bottomland hardwood forests for roosting and foraging habitat: Nycticeius humeralis (evening bat), Lasiurus seminolus (Seminole bat), Lasiurus borealis (eastern red bat), Perimyotis subflavus (tricolored bat), Corynorhinus rafinesquii (Rafines que's big-eared bat), Lasiurus cinereus (hoary bat), Lasio nycteris noctivagans (silver-haired bat), and Myotis austroriparius (southeastern myotis) (Ammerman et al., 2012;Weinkauf, 2015). ...
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Understanding foraging habits can be important for elucidating the ecology of any species and for designing appropriate conservation strategies. Common methods for determining bat diets, such as morphological examination of fecal material or recovery of prey fragments under feeding roosts, can be biased towards larger prey with harder exoskeletons by underestimating frequency/occurrence of smaller, softer bodied prey items. Our objectives were to determine prey selection for several common chiropteran species of bottomland hardwood forests in east Texas and to evaluate the use of DNA barcoding for dietary studies by comparing dietary composition to prey availability in four species of bats. We amplified the cytochrome coxidase subunit 1 gene from fecal samples collected from 19 bats of four species and identified arthropods by comparison to the Barcode of Life Data System database. We compared frequency of occurrence in fecal samples to frequency in concurrent night-flying insect sampling. We identified nine insect species from three orders consumed by Perimyotis subflavus, nine species from four orders consumed by Lasiurus seminolus, seven species from three orders consumed by Nycticeius humeralis, and 11 species from two orders consumed by Lasiurus borealis. Coleoptera was the most abundant order available by biomass, but beetles were never found in fecal samples from L. seminolus (n = 5) or L. borealis (n = 7) bats. However, Coleoptera comprised a substantial portion of prey identified from P. subflavus (n = 2) and N. humeralis samples (n = 5). Lepidopteran prey items were found in 13 of 19 bat fecal samples across all species but represented < 7% of arthropod biomass. Although dipteran species were a negligible portion (< 1%) of the available biomass, large numbers of dipterans were identified in fecal samples from all species of bats (13 of 19 samples across all species). Lasiurus seminolus and L. borealis may be selecting prey based on digestibility rather than availability; whereas, both N. humeralis and P. subflavus exhibited a more opportunistic approach to foraging. Based on comparison to other studies of bat diets, traditional techniques for analyzing diet from fecal samples are likely underrepresenting soft-bodied arthropods like dipterans.
... A few species were by sight and documented only by photographs because of their rarity at the site or because the steep slope of Spring Creek made a collection impossible. References used for specimen identification included Great Plains Flora Association (1986), Diggs et al. (1999), Yatskievyich (1999), Barkworth et al. (2007), and Tyrl et al. (2015). In addition to our collections, we searched the University of Central Oklahoma Herbarium (CSU) database and added a few previously collected species from the park. ...
... Gymnosperms and lower vascular plants were excluded for the purpose of computing indices. Most species were identified in the field, while certain taxa such as members of the Cyperaceae (Carex, Cyperus, and Eleocharis) and Poaceae, which require higher magnification and specialized taxonomic keys, were collected and identified later using a variety of regional, state, and national keys (Diggs et al., 1999;Flora of North America Editorial Committee, 1993;Tyrl et al., 2009). ...
Article
Biological integrity is continuously threatened by human activity. Impacts to biological health may be inferred directly (i.e. bioassessment), or estimated indirectly using rapidly collected field data or computer-based data layer analysis. This study tests whether surrounding land cover alteration (crops, pasture, and development in 200-m buffer) can predict and classify wetland biological health as represented by floristic quality (FQ) and taxonomic distinctness (TD). From surveys of 106 non-forested wetlands in Oklahoma during 2012–2015, we found a limited ability for land use to estimate site-specific FQ and TD values. Although the combined land uses were not a strong predictor overall, pasture land use by itself provided a weak to moderate surrogate when precipitation and ecoregion were taken into account. Floristic quality metrics and average TD decreased with increasing pasture in the 200-m buffer. Land use performed fairly well in classifying sites as biologically intact or not different from a least-altered state (5% FQ and 9% TD misclassification rate), but performed poorly in classifying sites as biologically impaired or deviating from a least-altered state (36% FQ and 24% TD misclassification rate). Importantly, classification analysis suggested that limited land use may separate higher FQ from moderate and lower FQ, whereas more intensive land use may separate lower average TD from moderate and higher average TD. This suggests that both measures (FQ and average TD) are needed for a more complete classification of wetland biological response to anthropogenic disturbance. Despite growing interest in relatively rapid or low-cost methods of wetland assessment, our results do not support using such methods in lieu of direct bioassessment.
... All other specimens in the flora area are attributable to M. hirtelliflora. Matelea decipiens has been included in the flora of North Central Texas (Diggs et al. 1999) where it is noted as being present on the eastern margin of the flora area. We have seen specimens of M. hirtelliflora in this region from Grayson, Hunt, Red River, and Van Zandt counties, but no specimens of M. decipiens. ...
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A new species of milkweed vine from Texas, Matelea hirtelliflora (Apocynaceae), is described and illustrated. This species is similar to congeners in the southeastern United States, but is distinguished by hirtellous corollas with shorter petals than its presumed closest relatives and by corona lobes with fleshy segments, each with two triangular projections. The species is illustrated and compared to similar species of eastern Texas and the eastern United States. A key is provided for the species of Matelea in eastern Texas and extreme southeastern Oklahoma, and a distribution map is provided for the new species.
... Vegetation at the TGPP is dominated by C4 grasses big bluestem (Andropogon gerardii Vitman), Indian grass (Sorghastrum nutans [L.] Nash), switchgrass (Panicum virgatum L.), and little bluestem (Schizachyrium scoparium [Michx.] Nash) (Diggs et al. 1999). Topography is gently rolling with soils derived from shale, limestone, and sandstone. ...
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Fire and grazing are interactive disturbance processes that are important to the structure and function of grassland ecosystems. Studies of nitrogen (N) availability report different effects following grazing and fire. However, these studies have largely neglected the spatially controlled interaction between fire and grazing. The objective of our work was to evaluate an application of the fire-grazing interaction model on N availability in a tallgrass prairie. We compared patches within a shifting mosaic landscape where each patch varied in time since focal disturbance (fire and intense grazing disturbance). We also evaluated N availability on a burned and grazed landscape where fires and moderate grazing occurred annually and uniformly across the entire landscape. These treatments were both burned and grazed where the only difference was spatial and temporal variability in fire application and grazing disturbance. Samples were collected from upland sites in May of 2003 and 2004. Total soil inorganic N (NH4+/-N + NO3-N) and a growth chamber experiment with hard red winter wheat (Triticum aestivum L. cv. Jagger) were used to evaluate potential N availability. Our study produced patterns of N availability that are more similar to studies of grazing lawns where N availability is enhanced by focal grazing than from studies of fire without grazing. Overall,our study demonstrates that fire and grazing are interactive. Unburned patches have minimal grazing pressure and low N availability. Fire-grazing interaction may provide a management alternative that enables sustainable livestock production, through increased carrying capacity in focally disturbed patches, concomitant with biological diversity in tallgrass prairie.
... Although it has been surmised that herbaceous legumes adapted to the hot, dry summers and cold winters of the southern Great Plains were common before the advent of barbed wire (Weaver 1954;Lewis et al. 1974), these species have largely succumbed to overgrazing and monoculture of exotics. Diggs et al. (1999) identified more than 20 genera containing numerous perennial herbaceous legume species found in north-central Texas, but few of these have been considered for cultivation. ...
Article
Native seed mixes for rangeland seeding, prairie restoration, or cultivated pasture can benefit from a greater variety of forbs that more closely reflect the original vegetation of the southern Great Plains. Fifteen native, perennial herbaceous legumes were collected in central Texas and evaluated for herbage production, mineral content, and fiber concentration of established plants in research plots over 2 years. Downy milk-pea (Galactia volubilis [L.] Britton) was productive, regardless of rainfall, whereas prairie acacia (Acacia angustissima [Mill.] Kuntze var. hirta [Nutt.] B.L. Rob.) and Illinois bundle-flower (Desmanthus illinoensis [Michx.] MacMill. Ex. B.L. Rob. Fernald) out-yielded others in year 3 when rainfall was the greatest. Herbage crude protein averaged approximately 100 g kg-1 for bush-clovers (Lespedeza spp.) compared to bundle-flowers (Desmanthus spp.), which exceeded 200 g kg-1; the latter also was high in herbage phosphorus. Herbage neutral detergent fiber ranged from 300 to more than 500 g kg-1, acid detergent fiber ranged from 140 to 360 g kg-1, and acid detergent lignin ranged from 36 to 140 g kg-1, a wide range from which to select if animal nutrition is a primary criterion. Seed production was evaluated within a subset of 8 entries submitted to periodic herbage removal or left intact throughout the season. Three bundle-flowers yielded the greatest mass and seed number, but were negatively affected by harvest, unlike prairie acacia. Herbage and seed characteristics indicate there are promising perennial herbaceous legumes in the southern Great Plains that can be included in native seed mixes.
... Prairie mounds were associated with burrows 9.0% of the time. Prairie mounds are slightly raised areas in grasslands (Diggs et al. 1999;Goetze et al. 2007) that are likely caused by swelling and shrinkage of clay soils or differential erosion. These raised areas are used by Texas kangaroo rats for burrow construction. ...
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VEGETATION ASSOCIATED WITH TEXAS KANGAROO RAT (DIPODOMYS ELATOR) BURROWS IN WICHITA COUNTY, TEXAS Allan D. Nelson, Jim R. Goetze and James S. Henderson Department of Biological Sciences, Box T-0100, Tarleton State University, Stephenville, Texas 76402 Abstract.–Vegetation ranges, means, and standard deviations associated with 46 burrows of the Texas kangaroo rat (Dipodomys elator) are reported for the first time from Wichita County, Texas. Most burrows were associated with honey mesquite and fence rows. Natural burrow associations such as shrubs occurred about 40% of the time and opportunistic use of man-made disturbances such as fence rows occurred about 60% of the time. Burrows in Wichita County are mostly different from those in Hardeman and Motley counties having more forbs, less grass, and larger amounts of bare ground. These differences are likely due to moderate to heavy grazing associated with the burrows from Wichita County. High densities of introduced grasses and changes in land uses that decrease grazing such as conservation programs cause the vegetation to become denser. These types of densely vegetated habitats are not preferred by Texas kangaroo rats in Wichita County.
... & Rupr.). Nomenclature follows Diggs, Lipscomb, and O'Kennon (1999). ...
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In a small plot study we used a systematic additive design to evaluate at what severity and frequency of defoliation sideoats grama (Bouteloua curtipendula) would remain competitive and recover from defoliation while growing with meadow dropseed (Sporobolus compositus). In the 3-year study plants were transplanted from pots into the experimental design when equal in size. When B. curtipendula was selectively defoliated moderately or severely, at both 30- and 60-day intervals, it still produced as much as when undefoliated growing with undefoliated S. compositus. Moderately defoliated B. curtipendula did not reduce biomass yield of S. compositus growing with it compared to when S. compositus was growing alone. When both plants were non-selectively defoliated severely, S. compositus responded very weakly and B. curtipendula recovered at the same rate as it had under the other defoliation treatments. The total biomass produced by both species growing together was highest when B. curtipendula was moderately defoliated. As soil moisture was not limited in this experiment we do not believe our results refute the hypothesis that selective grazing by livestock in these ecosystems has contributed to a reduction of B. curtipendula relative to S. compositus. Although S. compositus was reduced more than B. curtipendula by heavy nonselective defoliation this treatment is unlikely to produce desirable results in the long term as the highest total vegetation production occurred when B. curtipendula was moderately defoliated.
... Distributional and other data was obtained from the Synthesis of the North American Flora (Kartesz 2013), Tropicos (Tropicos.org.), Flora of North America and Digital Flora of Texas databases, literature on Texas flora (Correll & Johnston 1970;Johnston 1990;Turner et al. 2003;Diggs et al. 1999), many online databases on different taxonomic groups (like G. Nesom, Astereae database), and other literature sources. After revealing general distribution outlines for each species of the flora, congruent ranges of two or more species were classified into geographic elements using the classification system of geographic elements (Saghatelyan 2009) developed on the example of the BB flora. ...
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