[Federal Register: June 29, 1999 (Volume 64, Number 124)]
[Proposed Rules]               
[Page 34755-34756]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]



Fish and Wildlife Service

50 CFR Part 17

Endangered and Threatened Wildlife and Plants; 90-day Finding for 
a Petition To List the Plant ``Esenbeckia runyonii'' (Limoncillo) as 

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of petition finding.


SUMMARY: We, the U.S. Fish and Wildlife Service, announce a 90-day 
finding for a petition to list Esenbeckia runyonii (limoncillo) as 
endangered under the Endangered Species Act of 1973, as amended. This 
small tree is known from Cameron County, Texas, and from the states of 
Tamaulipas, Nuevo Leon, San Luis Potosi, Queretaro, and Hidalgo in 
Mexico. We find that the petition failed to present substantial 
information indicating that listing this species may be warranted.

DATES: The finding announced in this document was made on June 3, 1999.

ADDRESSES: Data, information, comments, or questions concerning this 
petition finding should be submitted to 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. The petition finding, supporting data, and comments are 
available for public inspection, by appointment, during normal business 
hours at the above address.

FOR FURTHER INFORMATION CONTACT: Robyn Cobb, c/o Texas A&M University-
Corpus Christi Field Office (see ADDRESSES section) (telephone 512/994-
9005; facsimile 512/994-8262).



    Section 4(b)(3)(A) of the Endangered Species Act (Act) of 1973, as 
amended (16 U.S.C. 1531 et seq.), requires that we

[[Page 34756]]

make a finding on whether a petition to list, delist, or reclassify a 
species presents substantial scientific or commercial information to 
demonstrate that the petitioned action may be warranted. This finding 
is to be based on all information available to us at the time the 
finding is made. To the maximum extent practicable, we make this 
finding within 90 days of the date the petition was received, and 
notice of the finding must be published promptly in the Federal 
Register. If the finding is that substantial information was presented, 
we are also required to promptly commence a review of the status of the 
species involved if one has not already been initiated under our 
internal candidate assessment process.
    We have made a 90-day finding on a petition to list the plant 
Esenbeckia runyonii (limoncillo). The petition, dated June 28, 1994, 
was submitted by Joe Ideker, Secretary of the Native Plant Project, and 
was received by the Service on July 5, 1994. The petitioner requested 
that we list E. runyonii as endangered. Action on this petition was 
delayed by a listing moratorium (Public Law 104-6, April 10, 1995) and 
rescission of listing program funding in Fiscal Year 1996. This 
moratorium was subsequently lifted and listing program funding restored 
on April 26, 1996. On May 16, 1996 (61 FR 24722) the Service issued 
guidance for priorities in restarting the listing program. This 90-day 
finding was precluded by the Service's listing priority guidance for 
Fiscal Year 1997, finalized December 5, 1996 (61 FR 64475). With the 
publication of listing priority guidance for Fiscal Years 1998 and 1999 
on May 8, 1998 (63 FR 25502) the Service returned to a more balanced 
listing program. The processing of petition findings to add species to 
the list of threatened and endangered species have significant 
conservation benefit and these actions are now placed in Tier 2.
    The petitioner states that all but one of the four (perhaps five) 
historically known U.S. populations of this small tree have been lost 
due to habitat destruction and that the remaining U.S. population 
consists of 15 plants occurring on less than 0.4 hectare (ha) (1 acre 
(ac)) of a Lower Rio Grande Valley National Wildlife Refuge (LRGV-NWR) 
tract. The petitioner states that this population is vulnerable to 
destruction from catastrophic events such as hurricanes, freezes, or 
fires. The petitioner mentions two unverified groups of E. runyonii 
plants in a Brownsville, Texas, park that are threatened by 
construction of a road to the Los Tomates Bridge. We investigated these 
plants and found them to be Crescentia alata, a trifoliate-leaved 
species in the bignonia family. The petitioner notes that other E. 
runyonii populations occur in Mexico, but provides no information on 
these populations.
    Cameron County, Texas, on the U.S./Mexico border, is the northern 
range limit of E. runyonii. Populations in Mexico are known from the 
states of Tamaulipas, Nuevo Leon, San Luis Potosi, Queretaro, and 
Hidalgo (F. Gonzalez-Medrano, Instituto de Biologia, Mexico City, 
Mexico, in litt. 1994; Kaastra 1982; A.M. Olivo, Instituto de Ecologia 
y Alimentos, Ciudad Victoria, Tamaulipas, Mexico, in litt. 1994; J.M. 
Poole, Texas Parks and Wildlife Department, Austin, Texas, in litt. 
1994). Information from herbarium specimens at the Missouri Botanical 
Garden (J.M. Poole, in litt. 1994), Universidad Autonoma de Tamaulipas 
(A.M. Olivo, in litt. 1994), Universidad Nacional Autonoma de Mexico, 
Mexico, D.F. (F. Gonzalez-Medrano, in litt. 1994), and Kaastra (1982) 
indicate at least 45 collection sites in Mexico. Chiang (1989) notes a 
collection by Pringle in Nuevo Leon that may represent an additional 
site. The species is also known from the canyons of the Sierra de 
Picachos (Nuevo Leon) and the El Cielo (Tamaulipas) bioreserve (C. 
Best, LRGV-NWR, Alamo, Texas, pers. comm. 1994).
    Esenbeckia runyonii populations in Mexico occur primarily in moist 
canyons on rocky talus slopes (C. Best, pers. comm. 1994; F. Gonzalez-
Medrano, in litt. 1994). This habitat is vastly different from the 
floodplain delta of the Rio Grande where the species occurs in the 
United States.
    The petition indicates a willingness to list only the Texas 
population of this plant until further studies are done on the 
populations in Mexico. The Act allows the listing of distinct 
population segments of vertebrate fish or wildlife species, but does 
not extend the same option to plants or invertebrate animals. The 
listing of any plant or invertebrate animal must include all 
populations within the species' historical range.
    We have reviewed the petition and appended data, and other 
literature and information available in our files. On the basis of the 

best scientific and commercial information available, we find that the 
petition does not present substantial information that listing this 
species may be warranted. The petition includes no information 
regarding distribution, population sizes, or threats to E. runyonii in 
Mexico, which constitutes most of the species' documented range 
(Kaastra, 1982). Information readily available to us indicates that 
while the U.S. populations have been reduced from four to one, the 
populations in Mexico appear to be relatively abundant and under no 
immediate threat that would justify listing the species as endangered 
or threatened.

References Cited

    Chiang, F. 1989. Casimiroa greggii, formerly in Sargentia 
(Rutaceae) Taxon 38:116-119.
    Kaastra, R.C. 1982. Flora Neotropica, Monograph Number 33, 
Pilocarpinae (Rutaceae). New York Botanical Garden, Bronx, New York.
    Author: The primary author of this document is Angela Brooks, 
formerly of the Corpus Christi Ecological Services Field Office (See 


    The authority for this action is the Endangered Species Act (16 
U.S.C. 1531 et seq.).

    Dated: June 3, 1999.
Jamie Rappaport Clark,
Director, Fish and Wildlife Service.
[FR Doc. 99-16418 Filed 6-28-99; 8:45 am]