[Federal Register: November 22, 1999 (Volume 64, Number 224)]

[Rules and Regulations]               

[Page 63745-63752]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]





Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AE54


Endangered and Threatened Wildlife and Plants; Determination of 

Endangered Status for the Plant Lesquerella thamnophila (Zapata 


AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.


SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine 

the plant Lesquerella thamnophila (Zapata bladderpod) to be an 

endangered species under the authority of the Endangered Species Act 

(Act) of 1973, as amended. Lesquerella thamnophila is currently known 

from four locations in Starr and Zapata Counties, Texas. Increased 

urban development, roadway construction, invasion of exotic species, 

increased oil and gas activities, alteration and conversion of native 

plant communities to improved pastures, overgrazing, and vulnerability 

from low population numbers threaten this species.

EFFECTIVE DATE: This final rule is effective December 22, 1999.

ADDRESSES: The complete file for this rule is available for inspection, 

by appointment, during normal business hours (8:00 am to 4:30 pm, 

Monday through Friday), at the U.S. Fish and Wildlife Service, 

Ecological Services Field Office, c/o Texas A&M University-Corpus 

Christi, Campus Box 338, 6300 Ocean Drive, Corpus Christi, Texas 78412.

FOR FURTHER INFORMATION CONTACT: Field Supervisor of the Corpus Christi 

Ecological Services Field Office at the

[[Page 63746]]

above address (Telephone 316-994-9005; Facsimile 361-994-8262).



    Lesquerella thamnophila, a member of the Brassicaceae (mustard) 

family, was first collected in Zapata County, Texas, by R. C. Rollins 

in 1959. The species was named Lesquerella thamnophila in 1973 by R.C. 

Rollins and E.A. Shaw in their work on the genus Lesquerella (Rollins 

and Shaw 1973). The few collected specimens of Lesquerella thamnophila 

have all come from Starr and Zapata Counties in southern Texas.

    Lesquerella thamnophila is a pubescent (hairy), somewhat silvery-

green herbaceous (herblike) perennial plant, with sprawling stems 43-85 

centimeters (cm) (17-34 inches (in)) long. The plant exhibits a taproot 

system indicating a perennial life habit. It possesses narrow basal 

leaves 4-12 cm (1.5-4.8 in) long, and 7-15 millimeters (mm) (0.3-0.6 

in) wide, with entire to wavy or slightly toothed margins. Stem leaves 

are 3-4 cm (1-1.5 in) long and 2-8 mm (0.1-0.3 in) wide, with margins 

similar to basal leaves. The inflorescences (arrangement of flowers on 

a single stalk) are loose racemes of bright yellow-petaled flowers (the 

flowers are arranged along an axis with the lower flowers maturing 

first), which appear at different times of the year depending upon 

timing of rainfall. Fruits are round and 4.5-6.5 mm (0.2-0.8 in) in 

diameter on short, downward curving pedicels (slender stalks) (Poole 


    Physical and climatic characteristics of Starr and Zapata Counties 

include level to rolling topography and an average of 45-51 cm (18-20 

in) of precipitation, with major peaks of rainfall in September and 

May. Infrequent but heavy downpours associated with hurricanes and 

tropical storms contribute to wide fluctuations in rainfall from year 

to year, and skew the historical mean well above the yearly median. 

Drought, a recurring event in south Texas, has a profound effect on 

native vegetation. The range of Lesquerella thamnophila has been under 

an extreme drought situation for a number of years, making it likely 

that the plant would take advantage of any measure of rainfall to 

flower and reproduce. The numbers of plants present in known 

populations appear to fluctuate dramatically in response to 

precipitation (Poole 1989).

    Lesquerella thamnophila can occur on graveled to sandy-loam upland 

terraces above the Rio Grande floodplain. The known populations are 

associated with three Eocene-age geologic formations--Jackson, Laredo, 

and Yegua, which have yielded fossiliferous (containing fossils) and 

highly calcareous (containing calcium carbonate) sandstones and clays.

    Known Starr County populations occur within the Jimenez-Quemado 

soil association and on Catarina series soils. Jimenez-Quemado soils 

are well-drained, shallow, and gravelly to sandy loam underlain by 

caliche (a hard soil layer cemented by calcium carbonate). This soil 

association is broad, dissected, and irregularly shaped, and occurs on 

huge terraces 6-15 meters (20-50 feet) above the floodplains of the Rio 

Grande. In most areas, the Jimenez soils occupy the slope breaks 

extending from the tops of ridges to the bottoms of the slopes, and 

narrow valleys between. Quemado soils occur as narrow areas on 

ridgetops, where the slope range is 3-20 percent. Steep escarpments can 

be present with rocky outcrops adjacent to the river floodplain. 

Catarina series soils consist of clayey, saline upland soils developed 

from calcareous, gypsiferous (containing gypsum), and or saline clays 

that usually contain many drainages and erosional features. The 

underlying material of the soils contain calcareous concretions (a 

rounded mass of mineral matter), gypsum crystals, and marine shell 

fragments (Thompson et al. 1972).

    Bladderpod populations in Zapata County occur within the Zapata-

Maverick soil association. Zapata soils are shallow, loamy or mixed, 

hyperthermic (high temperature), well-drained, and nearly level with 

undulating slopes ranging from 0 to18 percent, primarily on uplands 

occurring over caliche. The upper portion of the soil horizon ranges 5-

25 cm (2-10 in), with course fragments consisting of few to 25 percent 

of angular caliche 2.5-20 cm (1-8 in) long, and combined with chert 

gravel. Maverick soils consist of upland clayey soils occurring over 

caliche with underlying calcareous material containing shale and gypsum 

crystals (Thompson, et al. 1972). The upper zone consists of a 

moderately deep soft shale bedrock, sloping 1-10 percent, well-drained, 

and forming clayey sediments. Ancient deposition of rock material from 

the Rio Grande can be found in these portions of the soil, and rock and 

Indian artifact collection has become a pastime for residents and 

visitors in the area.

    Lesquerella thamnophila occurs as an herbaceous component of an 

open Leucophyllum frutescens (cenizo) shrub community that grades into 

an Acacia rigidula (blackbrush) shrub community. Both plant communities 

dominate upland habitats on shallow soils near the Rio Grande (Diamond 

1990). Other related plant species in the cenizo and blackbrush 

communities include Acacia berlandieri (guajillo), Prosopis sp. 

(mesquite), Celtis pallida (granjeno), Yucca treculeana (Spanish 

dagger), Zizyphus obtusifolia (lotebush), and Guaiacum angustifolium 

(guayacan). The coverage of an aggressively invasive, nonnative grass, 

Cenchrus ciliaria (buffelgrass), is extensive at three of the four 

extant sites and present at the fourth. Dichanthium annulatum 

(Kleberg's bluestem), which is used for erosion control on roadways, 

has also begun to invade natural areas and is present at all four 

Lesquerella sites, although not as extensively as buffelgrass. These 

shrublands are sparsely vegetated due to the shallow, fast-draining, 

highly erosional soils and semi-arid climate (Poole 1989).

    Livestock production is one of the major land uses for the area, 

although wildlife rangeland production for hunting and recreational use 

is becoming increasingly important. Major game species include white-

tailed deer (Odocoileus virginianus), quail (Colinus virginianus and 

Callipepla squamata), mourning dove (Zenaida macroura), turkey 

(Meleagris gallopavo), javelina (Pecari tajacu), and feral pig (Sus 

scrofa). Oil and natural gas production has become one of the most 

significant forms of income in the area due to a drought-induced 

decrease in cattle production.

    Overgrazing by livestock, root-plowing of shrubs, and subsequent 

planting of buffelgrass for rangeland improvement has eliminated much 

of the natural habitat. Buffelgrass, the forage plant used by most 

ranchers in the area, has invaded natural areas and out-competed native 

plants. Results from various invasive grass studies indicate that there 

may be shade and root competition as well as possible allelopathic 

effects (suppression of growth of one plant species by another due to 

release of toxic substances) on native forbs and grasses (Nurdin and 

Fulbright 1990).

    Lesquerella thamnophila occurred historically in Starr and Zapata 

Counties in the United States. We do not have information on Mexican 

populations, although we have contacted biologists and botanists in 

Mexico regarding its possible occurrence there and use as a medicinal 

plant. One response indicated that the plant was historically found in 

northern Mexico and was used as a poultice for open sores, wounds, and 

skin eruptions (Garcia in Litt. 1999).

    Since the first collection of Lesquerella thamnophila in 1959, and 

nine additional populations of the plant

[[Page 63747]]

have been located since then. Of the ten total known populations, four 

are believed to have been extirpated, two populations have not been 

surveyed since 1996 due to restricted access to private lands, and four 

sites are known to support extant populations.

Sites Believed To Be Extirpated

    R. C. Rollins originally discovered Lesquerella thamnophila in 1959 

in Zapata County, in a subdivision near Falcon Lake. This type locality 

was relocated in 1985, when approximately 1,000 plants were seen within 

a 5-hectare (ha) (15-acre (ac)) area. In 1986, the site was under a 

drought condition, and no plants were found. Plants were located again 

in 1988, but the numbers of plants were not recorded. Biologists from 

the Texas Parks and Wildlife Department (TPWD) relocated the site in 

1996, but saw no plants. Our personnel also found no plants in 

September 1998 or April 1999. The habitat at this site has become 

severely degraded. Soil has eroded into roadside ditches, buffelgrass 

has invaded the sloping hillside, and housing construction has 

eliminated much of the natural habitat of the area. The population has 

likely been extirpated from this site.

    In 1994, a site along an electric transmission line in southwestern 

Starr County was reported, however, no specimen was collected, and no 

plants have been seen at this site since then. In 1996, we discovered 

another site consisting of about 50 plants, less than 1.6 kilometers (1 

mile) northeast of the above-mentioned site along a roadside cut of 

Highway 83. Surveys for this population were performed in 1997-1999. In 

1998, one plant was observed, and in 1999, we found no plants at this 

site. In 1995, we discovered a small site in the Highway 83 right-of-

way south of the city of Zapata. The TPWD and Service biologists found 

one plant in 1998, but none were found in our April 1999 survey.

Extant Populations

    In April 1994, TPWD personnel discovered a new Starr County 

population of about 50 plants. We purchased this site as part of the 

Lower Rio Grande Valley National Wildlife Refuge (LRGVNWR) complex and 

began to monitor population numbers. In 1996, LRGVNWR biologists 

recorded a total of 131 plants, 84 of which exhibited no seedling 

productivity. In 1997, after high precipitation, the number of 

individuals increased to several thousand within an approximately 1-ha 

(2-3-ac) portion of the tract. In September 1998, we surveyed the site 

and found few individuals, but one plant had produced two fruits. The 

majority of plants seen were located under the canopy of associated 

brush species. Previous to the survey, high amounts of precipitation 

fell at the site, eroding soils, exposing the calcareous sandstone, and 

leaving the root structure of some Lesquerella thamnophila plants 

partially exposed. Where Lesquerella thamnophila individuals were 

protected by associated plants, topsoil was retained, and the species 

was less affected by heavy rains.

    In April 1999, after resumption of drought conditions, only a few 

Lesquerella thamnophila plants were found. However, in June we visited 

the site after 10-15 cm (4-6 in) of rain had fallen in the area and 

observed a large number of Lesquerella thamnophila plants flowering and 

producing fruit. During a survey one week later, few flowers, but many 

pods at various stages of development, were present. Close inspection 

of the plants revealed possible predation on seeds within developed 

pods. Botanists at the LRGVNWR are currently conducting habitat and 

community structure studies of Lesquerella thamnophila and associated 

species present at this site. The studies include investigations on 

habitat composition and productivity in relation to shade effects, 

relationships with other plant species, and the degree of successful 

species propagation.

    Another historical site in Zapata County, originally reported by 

Lundell and Lundell in 1941, was re-verified by TPWD in 1985 (Poole 

1989). Approximately 5,000 plants were found in this area on the east 

side of Highway 83 located near the Arroyo Tigre Chiquito bridge. In 

1986, during drought conditions, only 28 plants were seen. Plants were 

again located in 1988, but no counts recorded. The TPWD and the Texas 

Department of Transportation (TDOT) established a management agreement 

to protect the site, and we and TPWD monitor this population annually. 

The TPWD recorded 10 reproductive plants in 1991, no plants in 1992, 

and 7 nonreproductive plants in 1995. No plants were found during 1996-

1998 surveys, however, TDOT biologists found five plants at the site in 


    In 1996, TPWD discovered about 100 plants in a vacant lot near the 

Siesta Shores Subdivision in Zapata County, and in January 1998, 

located many rosettes (plants whose leaves are spread flat at ground 

level). We found one plant in July 1999, but extensive housing 

construction had begun, which eliminated much of the potential habitat. 

The population at the site could be extirpated unless conservation 

measures can be implemented in the very near future.

    In 1986, TPWD found 20 plants on a 2-ha (5-ac) tract of a privately 

owned ranch in southwestern Starr County (Poole 1989). The TPWD 

personnel observed the species again in 1994 but did not count 

individuals. The TPWD biologists observed 20 or fewer individuals in 

1996. In 1999, the site was confirmed to support plants, but no 

information is available on the number of plants observed.

Populations for Which Status Is Unknown

    Three Starr County populations, including the one above, were known 

from private ranch sites near the towns of Roma and Los Saenz. Two of 

the private ranch sites have not been visited by us or TPWD personnel 

because we do not have permission to access these sites. Therefore, we 

do not know the status of Lesquerella thamnophila at these sites.

Previous Federal Action

    Federal action involving this species began with section 12 of the 

Act (16 U.S.C. 1531 et seq.), which directed the Secretary of the 

Smithsonian Institution to prepare a report on plants considered to be 

endangered, threatened, or extinct. The report, designated as House 

Document No. 94-51, was presented to Congress on January 9, 1975. On 

July 1, 1975, we published a notice in the Federal Register (40 FR 

27823) accepting the Smithsonian report as a petition within the 

context of section 4(c)(2) of the Act, now section 4(b)(3)(A), and 

announcing that we would initiate a review of the status of those 

plants. Lesquerella thamnophila was included as threatened in the 

Smithsonian report and in our notice.

    On June 16, 1976 (41 FR 24523), we published a proposed rule to 

determine approximately 1,700 species of vascular plants as endangered. 

Lesquerella thamnophila was included in this proposal. However, the 

1978 amendments to the Act required the withdrawal of all proposals 

over 2 years old (although a 1-year grace period was allowed for those 

proposals already over 2 years old). On December 10, 1979 (44 FR 

70796), we published a notice withdrawing that portion of the June 16, 

1976, proposal that had not been made final.

    On December 15, 1980 (45 FR 82823), we published a list of plants 

under review for listing as threatened or endangered, which included 

Lesquerella thamnophila as a category 2 candidate. ``Category 2 

candidates'' were those

[[Page 63748]]

species for which available information indicated listing as threatened 

or endangered may have been appropriate, but for which substantial data 

were not available to support preparation of a proposed rule.

    Section 4(b)(3)(B) of the Act requires that we make findings on 

petitions within 12 months of their receipt. Section 2(b)(1) of the 

1982 amendments to the Act required that all petitions pending as of 

October 13, 1982, be treated as having been submitted on that date. The 

1975 Smithsonian report was accepted as a petition, and all the plants 

noted within the report, including Lesquerella thamnophila, were 

treated as being newly petitioned on October 13, 1982. In each 

subsequent year from 1983 to 1993, we determined that listing 

Lesquerella thamnophila was warranted, but precluded by other listing 

actions of higher priority, and that additional data on vulnerability 

and threats were still being compiled.

    A status report on Lesquerella thamnophila was completed August 8, 

1989 (Poole 1989). That report provided sufficient information on 

biological vulnerability and threats to warrant designating the species 

as a category 1 candidate and to support preparation of a proposed rule 

to list Lesquerella thamnophila as endangered. ``'Category 1 

candidates''' were those species for which we had substantial 

information indicating that listing under the Act was warranted.

    Notices revising the 1980 list of plants under review for listing 

as endangered or threatened were published in the Federal Register on 

September 27, 1985 (50 FR 39626), February 21, 1990 (55 FR 6184), and 

September 30, 1993 (58 FR 51171). Lesquerella thamnophila was included 

in the September 30, 1993, notice as a category 1 candidate.

    Upon publication of the February 28, 1996, Notice of Review (61 FR 

7605), we ceased using category designations and included Lesquerella 

thamnophila as a candidate species. Candidate species are those for 

which we have on file sufficient information on biological 

vulnerability and threats to support proposals to list them as 

threatened or endangered species. We retained Lesquerella thamnophila 

as a candidate species in the September 19, 1997, Review of Plant and 

Animal Taxa (62 FR 49398). On January 22, 1998 (63 FR 3301), we 

published a proposed rule to list Lesquerella thamnophila as 

endangered, without critical habitat, in the Federal Register. We 

invited the public and State and Federal agencies to comment on the 

proposed listing.

    The processing of this final rule conforms with our Listing 

Priority Guidance published in the Federal Register on October 22, 1999 

(64 FR 57114). The guidance clarifies the order in which we will 

process rulemakings. Highest priority is processing emergency listing 

rules for any species determined to face a significant and imminent 

risk to its well-being (Priority 1). Second priority (Priority 2) is 

processing final determinations on proposed additions to the lists of 

endangered and threatened wildlife and plants. Third priority is 

processing new proposals to add species to the lists. The processing of 

administrative petition findings (petitions filed under section 4 of 

the Act) is the fourth priority. The processing of critical habitat 

determinations (prudency and determinability decisions) and proposed or 

final designations of critical habitat will be funded separately from 

other section 4 listing actions and will no longer be subject to 

prioritization under the Listing Priority Guidance. This final rule is 

a Priority 2 action and is being completed in accordance with the 

current Listing Priority Guidance. We have updated this rule to reflect 

any changes in information concerning distribution, status, and threats 

since the publication of the proposed rule.

Summary of Comments and Recommendations

    The January 22, 1998, proposed rule and associated notification 

requested all interested parties to submit factual reports or 

information that might contribute to the development of a final rule. 

We published newspaper notices of the proposed rule in the Brownsville 

Herald on February 4, 1998; the Monitor (McAllen), the Valley Morning 

Star (Harlingen), the Rio Grande City Herald, and the Zapata News on 

February 5, 1998; and the February monthly issue of LareDOS (Laredo). 

The public comment period was open for 60 days, from January 22 to 

March 23, 1998.

    Five commenters, including the State and four individuals or 

groups, commented on the proposed rule. Three commenters opposed the 

listing; one commenter was neutral on listing; and one supported the 

listing. Issues raised by the commentors are discussed below.

    Issue 1: The listing of the plant poses a threat to landowners who 

earn their livelihood by cattle ranching or oil and gas production. 

Listing would also threaten the success of the North American Free 

Trade Agreement (NAFTA) by postponing construction of various roadways 

within south Texas.

    Response: The Act prohibits us from considering economic and other 

nonbiological factors in listing decisions. However, once a species is 

listed, we strive to minimize adverse economic impacts when considering 

how best to conserve listed species. The Act provides protection to 

listed plant species when landowners seek Federal permits, funding, or 

Federal loans for a land development project or other activities that 

may affect the species. Section 7(a)(2) of the Act requires Federal 

agencies to ensure that activities (such as road building) they 

authorize, fund, or carry out are not likely to jeopardize the 

continued existence of such a species or to destroy or adversely modify 

its critical habitat. Early coordination with State and Federal 

agencies can help minimize economic impacts and avoid unnecessary 

delays in project implementation.

    Endangered plants are not protected on private lands except when 

taken in knowing violation of a State law or regulation, including 

State criminal trespass law. However, we hope that listing the species 

will alert private landowners to the need to protect it and encourage 

them to work with us to develop conservation measures that will benefit 

both the landowner and the species.

    Issue 2: Additional surveys should be performed after rain events, 

and biological information should be gathered prior to listing, 

possibly to preclude listing.

    Response: Extirpations at historical sites and the apparent decline 

of extant Lesquerella thamnophila populations necessitates protecting 

the few known surviving plants under the Act. Should additional surveys 

and biological data indicate that the populations are more viable than 

most recently demonstrated, we would consider that information in 

formulating a recovery strategy for the species. Although the decrease 

in population number and size appears correlated with drought 

conditions, it is not known whether the remaining populations would 

rebound sufficiently following future rain events to justify not 

listing the species. Furthermore, delaying the listing process would 

increase the risk that more bladderpod populations would disappear. 

Because there are only four known populations scattered over a large 

geographical area, each loss decreases genetic variability and reduces 

the chances of the species' survival even after normal rainfall 

returns. The best scientific and commercial information available 

indicates that the species' existence is too precarious to delay the 

protections afforded by the Act.

Peer Review

    Our July 1, 1994, Peer Review Policy (59 FR 34270) requires that we 


[[Page 63749]]

the opinions of at least three independent specialists regarding 

pertinent scientific or commercial data on proposed species listings. 

We provided the proposed rule to 29 botanists and biologists outside 

the Service and asked for their review of the proposed action. We 

received responses from three biologists. Two supported listing the 

species and provided corrections to the proposed rule and other 

information. One respondent opposed listing on the grounds that further 

surveys would likely reveal additional populations, however, this 

scientist agreed that current information supports listing the species.

Summary of Factors Affecting the Species

    After a thorough review and consideration of all information 

available, we determined that Lesquerella thamnophila should be 

classified as an endangered species. We followed procedures found at 

section 4(a)(1) of the Act and the regulations implementing the listing 

provisions of the Act (50 CFR part 424). We may determine a species to 

be endangered or threatened due to one or more of the five factors 

described in section 4(a)(1). These factors and their application to 

Lesquerella thamnophila (Zapata bladderpod) (Rollins and Shaw), are as 


    A. The present or threatened destruction, modification, or 

curtailment of its habitat or range. Habitat destruction and 

modification are the primary threats to Lesquerella thamnophila. These 

threats include the introduction of nonnative pasture grasses, such as 

buffelgrass, and conversion of native rangeland to improved pasture, 

overgrazing, urban development, construction or improvement of highways 

and utility transmission systems necessary to support urban 

infrastructures, and oil and gas exploration and production. These 

types of activities have destroyed or altered more than 95 percent of 

the native habitat in south Texas (Jahrsdoerfer and Leslie 1988).

    A common practice in south Texas to improve rangeland for livestock 

production is to remove native shrubs through root-plowing or aerial 

herbicide application and then re-seeding the area with nonnative 

grasses. This practice potentially destroys Lesquerella thamnophila and 

its habitat. Buffelgrass has spread beyond improved pastureland and is 

now present throughout a large portion of south Texas. This invasive 

nonnative grass outcompetes and displaces native grasses, herbs, and 

small shrubs. Possible mechanisms for displacement of native species by 

invasive nonnatives could be loss of sites for native plant seedling 

establishment, light and moisture competition, and possibly 

allelopathic effects (Nurdin and Fulbright 1990).

    Much of south Texas has been affected by long-term grazing, and 

grazing continues to be an established practice on private lands. 

Vegetation of the semi-arid south Texas climate is less resilient to 

the impacts of long-term grazing than is the vegetation of wetter 

climates. This situation has led to severe depletion of the often 

highly erodible south Texas soils (Schlesinger, et al. 1990). It is 

impossible to calculate how much habitat occupied by Zapata bladderpod 

may have been lost due to the effects of long-term grazing and 

conversion of native rangeland to improved pasture.

    Lesquerella thamnophila is also threatened by potential urban 

development. Habitat at the type locality for this species has been 

reduced to a small vacant lot in a resort subdivision near Falcon 

Reservoir in the City of Zapata, Texas. This area is undergoing rapid 

development. Another Lesquerella thamnophila population, which had 

occurred in an abandoned trailer park, has disappeared. The current 

trend toward urbanization, including increased construction of 

convenience stores in the area, could extirpate remaining populations.

    South Texas is experiencing a rapid increase in highway 

improvements and construction to handle increased traffic stimulated by 

NAFTA. Existing roads that may be proposed for widening and/or paving 

lie adjacent to Lesquerella thamnophila populations. In addition, 

nonnative Kleberg's bluestem (Dichanthium annulatum) is used for 

errosion control, and that species is present at the known Lesquerella 


    South Texas is presently undergoing a significant increase in oil 

and gas exploration and production, especially in Zapata and Starr 

Counties. All phases of exploration and production have the potential 

to impact Lesquerella thamnophila populations and habitat. Seismic 

exploration requires clearing of extensive, temporary rights-of-way to 

facilitate equipment traffic. The construction of well pads, access and 

egress roads, electrical lines, and petroleum gathering lines from 

wells, if not planned properly, may destroy native habitat. The re-

seeding of nonnative grasses in pipeline rights-of-way not only hampers 

re-colonization by native species but further spreads invasive species 

that will displace native vegetation.

    B. Overutilization for commercial, recreational, scientific, or 

educational purposes. Although reported to have medicinal values, the 

species is not known to be a product in commercial trade.

    C. Disease or predation. The populations of Lesquerella thamnophila 

have shown no evidence of disease. However, Poole (1989) reports that 

cattle graze Lesquerella to the extent that numbers of plants in 

populations subjected to grazing are severely reduced compared to those 

in adjacent, ungrazed lands. In addition, our biologists surveying for 

the plant at a site owned and protected by the LRGVNWR found evidence 

of browsing by native animal species on the plants. While consumption 

by herbivores is a natural event, browsing can be a greater threat 

during drought conditions when range quality is reduced and other 

forage species have been reduced or removed. The small number of extant 

sites and the low number of plants can result in greater susceptibility 

to browsing than likely was present when populations were at historical 

levels. The plants in this portion of south Texas are sensitive to 

browsing during drought conditions due to the semi-arid environment and 

the sparseness of vegetation, even under ideal range conditions. 

Additionally, biologists have discovered evidence of predation on seed 

material of Zapata bladderpod during status surveys.

    D. The inadequacy of existing regulatory mechanisms. The species is 

not currently protected by any Federal or State laws or regulations.

    E. Other natural or man-made factors affecting its continued 

existence. Lesquerella thamnophila populations adjacent to maintained 

highway rights-of-way are exposed to herbicides used to control 

vegetation around bridges, guardrails, signs, and reflector posts. 

Maintenance crews may also use herbicides to kill woody species 

encroaching into the rights-of-way and along fence lines. Any plants 

within these areas are also threatened by maintenance practices such as 

blading, disking, and re-seeding with erosion control seed mixtures 

that contain primarily non-native invasive grasses.

    Only four known Lesquerella thamnophila populations are known to 

exist, and these have widely fluctuating numbers of plants from year to 

year. The low plant numbers usually seen in these populations during 

drought years can result in genetic drift which can restrict genetic 

variability reducing the species' ability to overcome environmental 

stresses. The reduced number of plants during drought years, with 


[[Page 63750]]

in some areas falling to zero above-ground vegetative individuals, also 

makes the species vulnerable to extinction from prolonged drought 

situations. The extreme rarity of this species makes populations 

vulnerable to extirpation and extinction from the variety of random 

environmental events mentioned, as well as human exploitation of its 


    In finalizing this rule, we carefully assessed the best scientific 

and commercial information available regarding the past, present, and 

future threats faced by the species. Based on this evaluation, the 

preferred action is to list Lesquerella thamnophila as endangered. The 

Act defines an endangered species as one that is in danger of 

extinction throughout all or a significant portion of its range. A 

threatened species is defined as one that is likely to become an 

endangered species in the foreseeable future throughout all or a 

significant portion of its range. Endangered status is appropriate 

because of the species' limited distribution, low population numbers, 

and imminent threats of habitat destruction. Threatened status would 

not accurately reflect the current status of this species.

Critical Habitat

    Critical habitat is defined in section 3 of the Act as--(i) the 

specific areas within the geographical area occupied by a species, at 

the time it is listed in accordance with the Act, on which are found 

those physical or biological features (I) essential to the conservation 

of the species and (II) that may require special management 

considerations or protection and; (ii) specific areas outside the 

geographic area occupied by a species at the time it is listed, upon a 

determination that such areas are essential for the conservation of the 

species. ``Conservation'' means the use of all methods and procedures 

needed to bring the species to the point at which listing under the Act 

is no longer necessary.

    In the proposed rule, we indicated that designation of critical 

habitat was not prudent for Lesquerella thamnophila because of a 

concern that publication of precise maps and descriptions of critical 

habitat in the Federal Register could increase the vulnerability of 

this species to incidents of collection and vandalism. We also 

indicated that designation of critical habitat was not prudent because 

we believed it would not provide any additional benefit beyond that 

provided through listing as endangered.

    In the last few years, a series of court decisions have overturned 

Service determinations regarding a variety of species that designation 

of critical habitat would not be prudent (e.g., Natural Resources 

Defense Council v. U.S. Department of the Interior 113 F. 3d 1121 (9th 

Cir. 1997); Conservation Council for Hawaii v. Babbitt, 2 F. Supp. 2d 

1280 (D. Hawaii 1998)). Based on the standards applied in those 

judicial opinions, we have reexamined the question of whether critical 

habitat for Lesquerella thamnophila would be prudent.

    Due to the small number of populations, Lesquerella thamnophila is 

vulnerable to unrestricted collection, vandalism, or other disturbance. 

We remain concerned that these threats might be exacerbated by the 

publication of critical habitat maps and further dissemination of 

locational information. However, we have examined the evidence 

available for Lesquerella thamnophila and have not found specific 

evidence of taking, vandalism, collection, or trade of this species or 

any similarly situated species. Consequently, consistent with 

applicable regulations (50 CFR 424.12(a)(1)(i)) and recent case law, we 

do not expect that the identification of critical habitat will increase 

the degree of threat to this species of taking or other human activity.

    In the absence of a finding that critical habitat would increase 

threats to a species, if there are any benefits to critical habitat 

designation, then a prudent finding is warranted. In the case of this 

species, there may be some benefits to designation of critical habitat. 

The primary regulatory effect of critical habitat is the section 7 

requirement that Federal agencies refrain from taking any action that 

destroys or adversely modifies critical habitat. While a critical 

habitat designation for habitat currently occupied by this species 

would not be likely to change the section 7 consultation outcome 

because an action that destroys or adversely modifies such critical 

habitat would also be likely to result in jeopardy to the species, 

there may be instances where section 7 consultation would be triggered 

only if critical habitat is designated. Examples could include 

unoccupied habitat or occupied habitat that may become unoccupied in 

the future. There may also be some educational or informational 

benefits to designating critical habitat. Therefore, we find that 

critical habitat is prudent for Lesquerella thamnophila.

    The Final Listing Priority Guidance for FY 2000 (64 FR 57114) 

states, ``The processing of critical habitat determinations (prudency 

and determinability decisions) and proposed or final designations of 

critical habitat will be funded separately from other section 4 listing 

actions and will no longer be subject to prioritization under the 

Listing Priority Guidance. Critical habitat determinations, which were 

previously included in final listing rules published in the Federal 

Register, may now be processed separately, in which case stand-alone 

critical habitat determinations will be published as notices in the 

Federal Register. We will undertake critical habitat determinations and 

designations during FY 2000 as allowed by our funding allocation for 

that year.'' As explained in detail in the Listing Priority Guidance, 

our listing budget is currently insufficient to allow us to immediately 

complete all of the listing actions required by the Act. Deferral of 

the critical habitat designation for Lesquerella thamnophila will allow 

us to concentrate our limited resources on higher priority critical 

habitat and other listing actions, while allowing us to put in place 

protections needed for the conservation of Lesquerella thamnophila 

without further delay.

    We plan to employ a priority system for deciding which outstanding 

critical habitat designations should be addressed first. We will focus 

our efforts on those designations that will provide the most 

conservation benefit, taking into consideration the efficacy of 

critical habitat designation in addressing the threats to the species, 

and the magnitude and immediacy of those threats. We will develop a 

proposal to designate critical habitat for the Lesquerella thamnophila 

as soon as feasible, considering our workload priorities.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 

threatened under the Act include recognition, recovery actions, 

requirements for Federal protection, preservation programs, and 

prohibitions against certain practices. Recognition through listing 

results in public awareness and conservation actions by Federal, State, 

and local agencies, as well as by private organizations and 

individuals. The Act provides for possible land acquisition, 

cooperation with the States, and requires that all Federal agencies use 

their authorities to carry out programs for the conservation of all 

listed species. The protection required of Federal agencies and the 

prohibitions against certain activities involving listed plants are 

discussed, in part, below.

[[Page 63751]]

    Section 7(a) of the Act, as amended, requires Federal agencies to 

evaluate their actions with respect to any species that is proposed or 

listed as threatened or endangered and with respect to its critical 

habitat, if any is being designated. Regulations implementing this 

interagency cooperation provision of the Act are codified at 50 CFR 

part 402. Section 7(a)(2) requires Federal agencies to ensure that 

activities they authorize, fund, or carry out are not likely to 

jeopardize the continued existence of a listed species, or destroy or 

adversely modify its critical habitat. If a Federal action may affect a 

listed species, the responsible Federal agency must enter into 

consultation with us.

    Federal agency actions that may require consultation as described 

in the preceding paragraph include, but are not limited to, brush 

clearing for flood control in arroyos within the jurisdiction of the 

International Boundary and Water Commission; technical assistance to 

landowners by the Natural Resource Conservation Service (formerly Soil 

Conservation Service) for activities funded by the Consolidated Farm 

Service Agency (formerly Agricultural Stabilization and Conservation 

Service); and rangeland herbicide or pesticide registration by the 

Environmental Protection Agency. The Federal Highway Administration 

will need to consider the occurrence of the species in activities such 

as widening existing roadways, or constructing new highways, as well as 

some maintenance practices. The U.S. Department of Housing and Urban 

Development will need to consider this species when it permits or funds 

water, sewer, and power services for settlements. The Federal Energy 

Regulatory Commission will need to consider the occurrence of the 

species when it approves interstate pipelines and electrical 

transmission lines, especially in previously undisturbed natural areas.

    The Act and its implementing regulations set forth a series of 

general prohibitions and exceptions that apply to all endangered 

plants. All prohibitions of section 9(a)(2) of the Act, implemented by 

50 CFR 17.61, apply. These prohibitions, in part, make it illegal for 

any person subject to the jurisdiction of the United States to import 

or export, transport in interstate or foreign commerce in the course of 

a commercial activity, sell or offer for sale in interstate or foreign 

commerce any such plant species; or to remove and reduce the species to 

possession from areas under Federal jurisdiction. In addition, the Act 

prohibits the malicious damage or destruction of such plants on areas 

under Federal jurisdiction; and the removal, cutting, digging up, or 

damaging or destroying of such plants in any other area, including non-

Federal lands, in knowing violation of any State law or regulation, or 

in the course of any violation of a State criminal trespass law. 

Certain exceptions to the prohibitions apply to agents of the Fish and 

Wildlife Service and State conservation agencies.

    The Act and 50 CFR 17.62 and 17.63 also provide for the issuance of 

permits to carry out otherwise prohibited activities involving 

endangered plants under certain circumstances. Such permits are 

available for scientific purposes and to enhance the propagation or 

survival of the species. We anticipate that few trade permits would 

ever be sought or issued because this species is not in cultivation nor 

common in the wild.

    Our policy (59 FR 34272) is to identify to the maximum extent 

practicable at the time a species is listed those activities that would 

or would not constitute a violation of section 9 of the Act. The intent 

of this policy is to increase public awareness of the effect of the 

listing on proposed and ongoing activities within a species' range.

    We believe that, based on the best information available at this 

time, the following actions will not result in a violation of section 

9, provided these activities are carried out in accordance with 

existing laws and regulations, including State laws and regulations, 

and permit requirements:

    (1) Activities authorized, funded, or carried out by Federal 

agencies (e.g., grazing management, agricultural conversions, flood and 

erosion control, residential development, recreational trail 

development, road construction, hazardous material containment and 

cleanup activities, prescribed burns, pesticide/herbicide application, 

construction or maintenance of pipelines or utility lines), when 

conducted in accordance with any reasonable and prudent measures given 

by us in a consultation under section 7 of the Act;

    (2) Casual, dispersed human activities on foot or horseback (e.g., 

birding, sightseeing, photography, camping, or hiking);

    (3) Activities on private lands that do not require Federal 

authorization and do not involve Federal funding, such as grazing 

management, agricultural conversions, flood and erosion control, 

residential development, road construction, and pesticide/herbicide 

application when consistent with label restrictions;

    (4) Residential landscape maintenance, including the clearing of 

vegetation around one's personal residence as a fire break.

    We believe that the following might result in a violation of 

section 9; however, possible violations are not limited to these 

actions alone:

    (1) Collection, damage, or destruction of Lesquerella thamnophila 

on Federal lands without a Federal permit. Lesquerella thamnophila 

occurs on Federal lands under our jurisdiction.

    (2) Collection, damage, or destruction of this species on non-

Federal land if conducted in knowing violation of State law or 

regulations, or in the course of any violation of a State criminal 

trespass law.

    (3) Interstate or foreign commerce and import/export without 

previously obtaining an appropriate permit. Permits are available for 

purposes of scientific research and enhancement or survival of the 


    Questions regarding whether specific activities may constitute a 

violation of section 9 should be directed to the Field Supervisor of 

our Corpus Christi Ecological Services Field Office (see ADDRESSES 

section). Requests for copies of the regulations regarding listed 

plants and inquiries about prohibitions and permits may be addressed 

to--U.S. Fish and Wildlife Service, Branch of Endangered Species/

Permits, PO Box 1306, Albuquerque, New Mexico 87103 (telephone 505-248-

6920; facsimile 505-248-6922).

National Environmental Policy Act

    We determined we do not need to prepare Environmental Assessments 

and Environmental Impact Statements, as defined under the authority of 

the National Environmental Policy Act of 1969, in connection with 

regulations adopted pursuant to section 4(a) of the Act. We published a 

notice outlining our reasons for this determination in the Federal 

Register on October 25, 1983 (48 FR 49244).

Required Determinations

    This rule does not contain any information collection requirements 

for which Office of Management and Budget (OMB) approval is required 

under the Paperwork Reduction Act (44 U.S.C. 3501 et seq.). An 

information collection related to the rule pertaining to permits for 

endangered and threatened species has OMB approval and is assigned 

clearance number 1018-0094. An agency may not conduct or sponsor, and a 

person is not required to respond to, a collection of information 

unless it displays a currently valid OMB control number. This rule does 

not alter that information collection requirement.

[[Page 63752]]

References Cited

Diamond, D. 1990. Plant Communities of Texas (series level). Texas 

Parks and Wildlife Department. Austin, Texas.

Jahrsdoerfer, S.E. and D.M. Leslie, Jr. 1988. Tamaulipan Brushland 

of the Lower Rio Grande Valley of South Texas: Description, Human 

Impacts, and Management Options. U.S. Fish and Wildlife Service, 

Biological Report. 88(36). 63 pp.

Nurdin, and T. E. Fulbright. 1990. Germination of Two Legumes in 

Leachate from Introduced Grasses. Journal of Range Management 43: 5.

Poole, J. 1989. Status Report on Lesquerella thamnophila. U.S. Fish 

and Wildlife Service, Albuquerque, New Mexico.

Rollins, R.C. and E.A. Shaw. 1973. The Genus Lesquerella. Harvard 

University Press, Cambridge, Massachusetts.

Schlesinger, W.H., J.F. Reynolds, G.L. Cunningham, L.F. Huenneke, 

and W.G. Whitford. 1990. Biological Feedbacks in Global 

Desertification. Science 247:1043-1047.

Thompson, C.M., R.R. Sanders, and D. Williams. 1972. Soil Survey of 

Starr County, Texas. U.S. Department of Agriculture. Soil 

Conservation Service, Temple, Texas.


    The primary authors of this document are Loretta Pressly, Kathy 

Nemec, and Angie Brooks. Major contributors to this document are Robyn 

A. Cobb and Ernesto Reyes (see ADDRESSES section).

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 

recordkeeping requirements, Transportation.

Final Regulation Promulgation

    For the reasons outlined in the preamble, we amend part 17, 

subchapter B of chapter I, title 50 of the Code of Federal Regulations, 

as follows:


    1. The authority citation for part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C. 

4201-4245; Pub. L. 99-625, 100 Stat. 3500, unless otherwise noted.

    2. Amend Sec. 17.12(h) by adding the following, in alphabetical 

order under FLOWERING PLANTS, to the List of Endangered and Threatened 


Sec. 17.12  Endangered and threatened plants.

* * * * *

    (h) * * *



--------------------------------------------------------    Historic range           Family            Status      When listed    Critical     Special

         Scientific name                Common name                                                                               habitat       rules


                    *                  *                  *                *                  *                  *                  *


                    *                  *                  *                *                  *                  *                  *

Lesquerella thamnophila..........  Zapata bladderpod...  U.S.A. (TX)........  Cruciferae.........  E                       671          N/A          N/A

                    *                  *                  *                *                  *                  *                  *


    Dated: November 16, 1999.

Jamie Rappaport Clark,

Director, Fish and Wildlife Service.

[FR Doc. 99-30378 Filed 11-19-99; 8:45 am]