Saturday, December 31, 2016

Texas populations of the Smooth Green Snake (Opheodrys/Liochlorophis vernalis)

An Annotated Bibliography for the Texas populations of the Smooth Green Snake (Opheodrys/Liochlorophis vernalis)

Compiled by Tom Lott [TEL] - Last updated on 31 December 2016
[These bibliographies and their annotations are an on-going project. I have many comments on papers that I have not yet posted but I will attempt to attend to this task as time allows. Comments proffered in the annotations are strictly my own opinions and should be taken as such. If you wish to comment or supply additional references that I have overlooked, you may contact me via E-mail. To correspond with me, I may be reached at:  tomlott[at]thornscrub[dot]com.  Thanks for reading, Tom Lott ]

Ashton, R. E. 1976. Endangered and threatened amphibians and reptiles in the United States. Soc. Stud. Amphib. Rept. Herp. Circular (5): 1-65. [Recommended "protection" for this form in Texas. Lists "current problem," as "habitat destruction," "B. Urbanization, road building, etc." Current Protection: (as of 1976) "none," Recommendation: "E. Consideration of a species’ habitat requirements when developing land or watershed and what impact such development will have on existing populations." And "F. A species that should be monitored within the state and if current trends of land use or habitat destruction continue, one of the above criteria should be enacted." {i.e., a) total protection a la ESA, b) total state level protection of species and its required habitat {emphasis mine}, and/or c) "Regulation of collection of the species via bag or possession limits, collecting season."} Interestingly, when Opheodrys vernalis was finally granted "protection" at the state level [not in 1977], only option "C" was considered, totally outlawing collection, but failing to address any of the habitat provisions above. – TEL]

Bailey, V. 1905. Biological Survey of Texas. North Am. Fauna 25: 1-222.  [Contains a reference to a specimen allegedly from the Panhandle community of Washburn, Armstrong County.  Bailey made no reference to the ultimate disposition of this specimen and Grobman (1941) was unable to locate it for his revision of the species 36 years later.  Grobman rejected this record due to his observation that, “The accepted records that are represented by reliable museum specimens and that are south of the junction of the Ohio and Mississippi Rivers are from the mountains, which is not true for any of the Texas locality records” (Grobman, 1941) - TEL]

Blair, W. F. 1958c. Distributional patterns of vertebrates in the southwestern United States in relation to past and present environments. In Zoogeography, ed. C. L. Hubbs, 433-68. Washington, D. C.: AAAS Publication (51).

Brown, B. C. 1950. An annotated check list of the reptiles and amphibians of Texas. Waco: Baylor University Studies. [In the introduction, lists Opheodrys vernalis among "doubtful species," ". . . omitted from the check list for lack of sufficient evidence of their natural occurrence in the state." Later, under the account for O. aestivus, he remarks: "The closely related Opheodrys vernalis has on various occasions been reported from Texas. However, Grobman [1941] has effectively proved these records invalid." Even though Brown recognizes Albert J. Kirn in his acknowledgements, no mention is made of Kirn’s alleged discovery of 2-3 specimens of O. vernalis, collected by Gabriel Marnoch at Helotes, in the collection of St. Mary’s University in San Antonio. Ironically, Brown’s manuscript was originally submitted as an M. S. thesis to the Texas A&M College under the direction of William B. Davis, who had reported a specimen of O. vernalis from Austin County, Texas in 1949. – TEL]
Conant, R. 1958. A field guide to reptiles and amphibians of the United States and Canada east of the 100th meridian. Boston: Houghton Mifflin Co.

Conant, R. 1975. A field guide to the reptiles and amphibians: Eastern and central North America. 2nd edition. Boston: Houghton Mifflin Co. [States that, though this is generally an upland snake, it occupies lowlands in southeastern Texas (p. 185). Cites habitat destruction as a cause of the fragmented distribution of western populations. "Members of the disjunct population in the grasslands of se. Texas may be light brown with an olive wash instead of green" (p. 186). The range map (#134) depicts a fairly large stippled area in se. Texas from Matagorda Bay to almost the Sabine estuary, with stippled dots at the panhandle locality (Armstrong County) and in southern New Mexico near Las Cruces. – TEL]
Conant, R and J. T. Collins. 1991. A field guide to the reptiles and amphibians: Eastern and central North America. Boston: Houghton Mifflin Co.

Conant, R and J. T. Collins. 1998. A field guide to the reptiles and amphibians: Eastern and central North America. 3rd edition (expanded) Boston: Houghton Mifflin Co.

Cope, E. D. 1900. The crocodilians, lizards, and snakes of North America. Annu. Rept. U.S. Natl. Mus. 1898: 155-1294.
Davenport, J. W. 1943. Field book of the snakes of Bexar County, Texas, and vicinity. San Antonio: Witte Memorial Museum. ["This snake is not considered a native of this part of the country but Mr. A. J. Kirn found three pickled specimens of O. vernalis in the collection of specimens by the late Gabriel Marnoch, labeled Helotes, Texas. Several collectors report having seen this snake in the Helotes region but none have been brought into the [reptile] garden." The "Reptile Garden" was associated with the Witte Memorial Museum in San Antonio. – TEL]
Davis, W. B. 1949. The smooth green snake in Texas. Copeia 1949(3): 233[On April 23, 1949, William B. Davis and a group of his students from Texas A&M College stopped along a roadside about 2.5 miles west of Sealey, Austin County, Texas to examine a temporary rain pool in the open prairie.  In the short grass of the highway right-of-way they discovered and collected a single specimen of O. vernalis.  Davis gave few details about the snake other than it had 137 ventrals and therefore was referable to Grobman’s newly proposed western race blanchardi (as an important voucher specimen, it is unthinkable today that neither the collection in which the specimen was  deposited [presumably the Texas Cooperative Wildlife Collection at Texas A&M, which Davis was instrumental in founding] nor its catalog number or sex were mentioned in the published note).
              Instead, Davis chose to confront Grobman’s apparent dogmatism in refusing to accept records of O. vernalis from Texas (as well as several other southern states) as genuine; Grobman in fact dismissed these records with the almost flip comment that they “are obviously in error.”  Davis’ irritation is apparent when he writes, “His main points of argument are that specimens were either outside his [emphasis Davis’] accepted range or that the collector’s data are unreliable.”  Davis instead proffered an analogy between the isolated Texas records for the frog
Rana areolata, which his group also collected at the same location, and the disjunct nature of O. vernalis populations in Texas.  “Because of this recent capture of vernalis, I am inclined to accept the records from Bosque, Ellis and Matagorda counties, Texas as authentic” (Davis, 1949).  Unfortunately for Davis, Grobman was eventually shown to be correct (perhaps for the wrong reasons) about the first two of those three localities.  (Davis 1949) - TEL]

Davis, W. B. 1953. Another record of the smooth green snake in Texas. Herpetologica 9(2): 165.  [Four years after reporting an O. vernalis from near Sealy, Austin Co., Texas (Davis 1949), the author reports on another specimen, a female, from 8 miles south of Sealy.  Scale counts are given, which also place this specimen in the subspecies blanchardi, as would be expected.  The snake was collected in a "meadow" and presented to the author.  The author then devotes the remaining three paragraphs of the short four paragraph paper to refuting Grobman's (1941, 1950) claims that the Texas specimens cannot be naturally occurring.  Unfortunately, Davis again refers to the Ellis County (Waxahachie) specimen, which was later shown to be a misidentification, and to the mysterious "southern Oklahoma" specimen (doubtless KU 2537, although not cited).  Again the disposition of the specimen is not stated (although again, presumably TCWC) - TEL]

Dixon, J. R. 1987. Amphibians and reptiles of Texas. W. L. Moody, Jr., Nat. Hist. Ser. 8. College Station: Texas A&M University Press.

Dixon, J. R. 1993. Supplement to the literature for the Amphibians and reptiles of Texas. 1987. Smithson. Herpetol. Info. Serv. 94: 1-43.

Dixon, J. R. 2000. Amphibians and reptiles of Texas. 2nd Ed. W. L. Moody, Jr., Nat. Hist. Ser. 25. College Station: Texas A&M University Press.  [As Liochlorophis vernalis, ssp blanchardi. Provides 34 literature records for this species, a county-based distribution map showing records for only four counties (Austin, Chambers, Harris, and Matagorda), and a black-and-white photo of a specimen from an unknown location by J. T. Collins. - TEL]

_______ . 2013. Amphibians and reptiles of Texas. 3rd Ed. W. L. Moody, Jr., Nat. Hist. Ser. 25. College Station: Texas A&M University Press.  [As Opheodrys vernalis.  Contains 38 citations for this taxon, a county-based distribution map with the same four counties, and a color photo of an individual from an unspecified locality by K. Wray.  Discusses the fact that Oldham and Smith (1991) presented eight differences between this species and O. aestivus in proposing the genus Liochlorophis for it, nevertheless reverting to Opheodrys in the current treatment.  Notes T. J. Hibbitts' extensive but unsuccessful efforts to obtain this species in SE Texas prairies. I have reviewed this book HERE. - TEL]

Dundee, H.A. and D.A. Rossman. 1989. The amphibians and reptiles of Louisiana. Baton Rouge: Louisiana State Univ. Press. [Includes no reference to L. vernalis – TEL]
Flores-Villela, O. 1993. Herpetofauna Mexicana. Carnegie Mus. Nat. Hist. Spec. Publ. (17):1-72.

Garman, S. W. 1892. On Texas reptiles. Bull. Essex Inst. 24: 1-12.

Garrett, J. M. and D. G. Barker. 1987. A field guide to the reptiles and amphibians of Texas. Austin: Texas Monthly Press.

Gehlbach, F. R., K. A. Arnold, K. Culbertson, D. J. Schmidly, C. Hubbs, and R. A. Thomas. 1975. TOES watch-list of endangered, threatened, and peripheral vertebrates of Texas. Tex. Org. Endang. Species Publ. 1: 1-12.

Gloyd, H. K. 1944. Texas snakes. Tex. Geogr. 8: 1-18.

Grace, J. W. 1980. Annotated checklist of the amphibians and reptiles Guadalupe Mountains National Park, Texas. Carlsbad Caverns Nat. Hist. Assn. [Under "possible species": "Smooth Green Snake, Opheodrys vernalis. Skeletal remains from upper west side, sighting from McKittrick Canyon; to be expected at intermediate elevations; secretive, color blends with vegetation." – TEL]
Grobman, A. B. 1941. A contribution to the knowledge of variation in Opheodrys vernalis (Harlan), with the description of a new subspecies. Misc. Publ. Mus. Zool. Univ. Mich. 50: 1-38.

Grobman, A. B. 1950a. The problem of the natural range of a species. Copeia 1950(3): 231-32.

Grobman, A. B. 1992. Metamerism in the snake Opheodrys vernalis, with a description of a new subspecies. J. Herpetol. 26(2): 175-86.

Grobman, A. B. 1992. On races, clines, and common names in Opheodrys. Herpetol. Rev. 23(1): 14-15.

Hill., W. H. 1966. Pleistocene snakes from a cave in Kendall County, Texas. Masters Thesis, Illinois State Univ. Library.

_________. 1971.  Pleistocene snakes from a cave in Kendall County, Texas.  Texas J. Sci. 22: 209-216.  [Apparently following Holman (1966a), was unable to determine any character other than size to distinguish O. vernalis from O. aestivus, but see Holman and Richards (1981). - TEL]

Holman, J.A. 1966a. The Pleistocene herpetofauna of Miller's Cave, Texas. Texas Jour. Sci.,
28:372-877.  [Assigned two vertebrae from this cave to O. aestivus, primarily on the basis of size. - TEL]

___________1969. The Pleistocene amphibians and reptiles of Texas. Michigan St. Univ. Mus. Publ. 4: 163-192.  [Summarizes records of fossil vertebrae (?) of an unknown species of Opheodrys from the Wisconsin Pleistocene deposits of Cave Without a Name (Kendall County;Hill 1966) and Miller's Cave (Llano County; Holman, 1966a, Patton, 1963), the former locality being very close to Marnock's area at Helotes in Bexar County - TEL]
______ and R.L. Richards. 1981.  Late Pleistocene occurrence in southern Indiana of the Smooth Green Snake, Opheodrys vernalis.  J. Herpetol. 15: 123-125.  [States that:"Opheodrys vernalis trunk vertebrae may be distinguished from those of O. aestivus on the basis of: (1) smaller size, (2) neural arch vaulted (somewhat depressed in O. aestivus), (3) neural spine lower, (4) neural canal ovaloid (round in O. aestivus), (5) paired vertebral processes all more gracile."  These vertebrae were found in southern Indiana, where "there are no modern records of this snake" and in association with fossils of an extinct armadillo; a wood rat (Neotoma floridana), which is relictual in southern Indiana; the Rice Rat (Oryzomys sp.), which occurs in the southern tip of Illinois and southernmost Kentucky, indicating much warmer winters in the late Pleistocene.  "It is interesting to note that an armadillo (Dasypus novemcinctus), a Wood Rat, a Rice Rat, and the Smooth Green Snake occur together today in a small area on the Texas Gulf Coast." - TEL]
______ and Winkler. 1987. A mid-Pleistocene (Irvingtonian) herpetofauna from a cave in southcentral Texas. Pearce-Sellads Ser. (44): 1-17. [Apparently cited in error by Walley (2003) as referring to Texas fossils of O. vernalis.  The only reference to this species in this paper is to O. vernalis fossils from Cumberland Cave in Maryland to show that the mid-Pleistocene fauna from the Fyllan Cave resembled that from such widely separated areas as Maryland, West Virginia, and central Texas, implying that the milieu supporting it was widespread (i.e., their Table 1). - TEL]

Huang, T. T., S. R. Lewis, and B. S. Lucas III. 1975. Venomous snakes. In Dangerous Plants, Snakes, arthropods, and marine life in Texas. 123-42. Washington, D.C.: U.S. Department of Health, Education, and Welfare.

Logan, L. E., and C. C. Black. 1979. The Quarternary vertebrate fauna of Upper Sloth Cave, Guadalupe Mountains National Park, Texas. 141-58. In Genoway, H.H. and R.J. Baker (eds.), Biological Investigation in the Guadalupe Mountains National Park, Texas.  Natl. Park Serv. Trans. Proc. Ser. 4:.

Lott, T. 2015.  The Verdant Enigma—Forgotten Allegations of the Smooth Green Snake (Opheodrys vernalis) from the Edwards Plateau of Texas. SWCHR Bulletin 5(1): 3-5.  [Revives accounts from the 1940s concerning the possible existence of specimens of this locally rare snake purportedly collected by Gabriel Marnoch at or near his home in Helotes, Texas. Assesses the extant fossil evidence that two different species of Opheodrys occurred on the Edwards Plateau during the Pleistocene and the possibility that undiscovered relict populations of this snake might possibly exist there. - TEL]  [PDF]
_______. 2016.  The Emerald Ghost: A History of the Smooth Green Snake (Opheodrys vernalis) in Texas
and Adjacent States (Serpentes: Colubridae). SWCHR Bulletin 6(1): 9-15.  [An updated summary of known specimens (vouchered and unvouchered) of this species from Texas and surrounding states. - TEL] [LINK]

McClure, W. L. 1969. A new record of Opheodrys vernalis blanchardi in Texas. Southwest. Nat. 14(1): 129.  [A remarkably terse little note describing the first Chambers County, Texas record of a species that had not been recorded in Texas (excluding the 1961 Werler specimens) for more than 12 years at the time.  McClure described the habitat as "coastal prairie with native short grasses the dominant vegetation.  Rice fields are nearby.  Elevation is 7 feet above sea level."  The female specimen was said to be light green in coloration and was deposited in the "collection" of a school district in the Houston area (Spring Branch Science Center #ZV 364) ! -- TEL]

McClure, W.L. 1974.  The western green snake, Opheodrys vernalis blanchardi Grobman.  Tex. Hwy. Dept. Environ. Brief 74-12-01:1-3
Mecham, J. S. 1979. The biogeographical relationships of the amphibians and reptiles of the Guadalupe Mountains. Nat. Park Serv. Trans. Proc. Ser. 4: 169-79.  ["The inclusion of Opheodrys vernalis {in the herpetofauna of the Guadalupe Mountains} is based               primarily on a recent sight record of the species in the McKittrick Canyon area by Mr. Tony Burgess, although a rancher some years ago gave the writer  a good description of what apparently was this species in the vicinity of the ruins of Queen, New Mexico (northern Guadalupe Mountains, 6000 ft).  The form is known as a sub-Recent fossil (Logan and Black 1977), and occurs nearby in the Sacramento Mountains."  - TEL]
Oldham, J. C., and H. M. Smith. 1991. The generic status of the smooth green snake Opheodrys vernalis. Bull. Md. Herpetol. Soc. 27(4): 201-15.  [Provides eight anatomical and physiological differences between O. vernalis and O. aestivus in erecting the genus Liochlorophis for the former. - TEL]
Owen, J. G. 1989. Patterns of herpetofaunal species richness: Relation to temperature, precipitation, and variance in elevation. J. Biogeogr. 16: 141-50.

Owen, J. G., and J. R. Dixon. 1989. An ecogeographic analysis of the herpetofauna of Texas. Southwest. Nat. 34(2): 165-80.

Patton, T. H. 1963. fossil vertebrates from Miller's Cave, Llano County, Texas. Bull. Texas Mem. Mus., 7:1-41.  [Mentions but does not discuss fossils of "Opheodrys sp." from this cave. - TEL]
Raun, G. G. 1965b. A guide to Texas snakes. Tex. Mem. Mus. Notes 9. ["It seems much out of habitat in Texas. . . . Texas distribution: Area 2 (reported from Ellis, Bosque, Austin, and Matagorda counties), rare, isolated populations. Remarks: could easily be confused with the green phase of the racer. Additional records of this snake in Texas are much to be desired." It should be pointed out, though, that specimens of Coluber constrictor of a size comparable to that of O. vernalis would typically still retain the blotched juvenile pattern on a non-green (or non-brown) ground coloration. – TEL]
Radaj, R. H. 1981. Life history notes. Opheodrys v. vernalis (Smooth Green Snake). Reproduction. Herpetol. Rev. 12(3): 80. [Not on Texas specimens, but cited by Tennant (1984) to show that brown-colored specimens are occasionally found in clutches throughout the range of the species. – TEL]

Shofner, R.M. 2011.  Smooth Green Snakes (Liochlorophis vernalis) in Kansas: A History and Rediscovery.  Jour. Kan. Herpetology 40: 8-9
Smith, H. M., and H. K. Buechner. 1947. The influence of the Balcones Escarpment on the distribution of amphibians and reptiles in Texas. Bull. Chi. Acad. Sci. 8(1): 1-16.

Smith, H.M. and A.B. Leonard. 1934. Distributional records of reptiles and amphibians in Oklahoma. American Midland Naturalist 15(2): 190-196. [Apparently the first record of this species in OK, but the record is remarkably unhelpful, intimating only that the specimen is from "southern Oklahoma" and that it resides in the University of Kansas Collection (no specimen number(!) nor collector is given). Thanks to Shane Lowe for this reference -- TEL] [PDF]

Stebbins, R. C. 1966. A field guide to western reptiles and amphibians. Boston: Houghton Mifflin Co.

Tanner, W.W. 1985. Snakes of western Chihuahua. Great Basin Nat. 45: 615-676.

Tennant, A. 1984. The snakes of Texas. Austin: Texas Monthly Press. [Under "abundance," . . . in Texas O. v. blanchardi is known from fewer than 10 specimens. All were collected on the coastal plain of Austin, Chambers, Harris and Matagorda counties, where the snakes have now been almost extirpated, according to Conant (1975), "because of the destruction of [their moist, shortgrass] habitats by agriculture and other human activities." States that Texas specimens have ranged from >10" to slightly >15" in length. Habitat: ". . . the Gulf coastal plains relic O. v. blanchardi occupy a mesic prairie community covered with native short grasses similar to the moist, meadowland macrohabitat preferred everywhere in this animal’s range." Behavior: "Most O. v. blanchardi have been found in Texas only after the high water of a severe storm or hurricane has covered wide areas of low-lying coastal plain, however, forcing these big-eyed little reptiles from the security of the burrows and thick vegetation in which they ordinarily hide: near Angleton two smooth greens {apparently Werler’s 1961 specimens} were seen crawling over clumps of grass on one of the few sections of land not covered by local floodwaters, while in Matagorda County another was discovered taking refuge on a slightly elevated road running through a grassy prairie that had just been inundated by heavy rain." Suggests, referring to Radaj (1981) on a clutch from the northern portion of the range, that an olive-brown color phase of this species is "apparently particularly likely to occur among the Texas population." The county map for Texas shows dots (designating literature records or museum specimens) for Austin, Chambers, and Matagorda counties, while Hartley and Harris counties sport X’s, indicating "confirmed observational record," even though Worthington’s (1973) Harris County record had been published eleven years earlier. – TEL]
Tennant, A. 1985. A field guide to Texas snakes. Austin: Texas Monthly Press.

Tennant, A. 1998. A field guide to Texas snakes. 2nd edition. Houston: Gulf Publishing.

Tiller, W. K., ed. 1960. Texas Herpetological Society News Letter (November, 1960, spirit copy.), p. 1-5. [Includes the tabulation of field collection results from the spring field meeting of the society at the Traylor Ranch, near Point Comfort, Calhoun County, Texas on April 30—May 1, 1960. A total of 328 specimens representing 43 species of herps were collected in an area not distant from other Opheodrys vernalis records (and in similar habitat). Although no O. vernalis were collected, the 129 member group did manage to find a single specimen of another similarly rare coastal species, Cemophora coccinea. – TEL]
Trauth, S.E., H.W. Robison, and M.V. Plummer. 2004. The amphibians and reptiles of Arkansas. Fayetteville: Univ. of Arkansas Press. [Under "Amphibian and Reptile Species Erroneously Reported from Arkansas," state that "The distributional limits of several species in neighboring states may actually extend into Arkansas, but Arkansas specimens have not been unequivocally verified. . . . Liopeltis vernalis . . . (Dellinger and Black, 1938)." – TEL]
Van Devender, T.R. and C.H. Lowe, Jr. 1977. Amphibians and reptiles of Yepomara, Chihuahua, Mexico. J. Herpetol. 11:41-50. ["Opheodrys vernalis blanchardi Grobman (Western green snake). Locality: 2.6 km N Pedernales or 38.4 km SE Guerrero on Mexico 16, 2185 m (UAZ 34416). A single specimen of O. vernalis was collected in plains grassland on the continental divide. This is the first record for the state of Chihuahua, and for Mexico. The nearest O. vernalis population known is in the Sacramento Mountains of New Mexico, northeast of El Paso, Texas, some 480 km to the northeast (MALB 769-770: NW Ruidoso). The disjunct populations of O. vernalis in Chihuahua and New Mexico suggest that these may be relicts of the Wisconsin glacial period when conditions were cooler and/or moister, and mesic vegetation more continuous between the Rocky Mountains and the Sierre Madre Occidental. This record of dispersal is especially interesting because O. vernalis is a terrestrial, non-riparian species." – TEL]
Vermersch, T.G. and R.E. Kuntz. 1986. Snakes of South Central Texas. Eakin Press, Austin, Texas.
[Although the authors acknowledge that two species of Opheodrys occur in Texas, they exclude O. vernalis from their work, contending that it does not occur in the south-central area covered in their book.  Consequently, even though there is a great deal of historical information in the introduction, there is no reference to the putative Marnoch specimens (allegedly from Helotes, Bexar County) discovered by A.J. Kirn in a natural history collection at St. Mary's University in San Antonio.  Vermersch (per. comm.) stated that much of Marnoch's material was actually collected at sites other than those surrounding his Helotes residence and that, if the O. vernalis records were valid at all, they might have come from a site on the Guadalupe River, some 22 miles north of Helotes. - TEL]

Walley, H. D. 2003. Liochlorophis, L. vernalis. Cat. Am. Amphib. Rept. 776.1-776.13. [An important update on the literature of this species, although it contains little new information concerning the status of Texas populations except for "A.B. Grobman (per. comm..) suggested that the Texas isolates were established via human agency . . .," indicating that Grobman still adheres to his original opinion. Provides a range map showing the four vouchered localities in Texas connected by a narrow shaded band, and an unspecified fossil record from central Texas (but not the Guadalupe Mountains). Also cites evidence provided in an abstract by Chiszar et al (1996) that Grobman’s subspecies of this taxon may, in fact, be valid rather than clinal extremes as has been previously suggested. – TEL]
Ward, R., E. G. Zimmerman, and T. L. King. 1990. Multivariate analyses of terrestrial reptile distribution in Texas: An alternate view. Southwest Nat 35(4): 441-45.

Webb, R.G. 1970. Reptiles of Oklahoma. Stovall Mus. Publ., Norman, Oklahoma[Under the heading "Unverified, Problematical, and Probable Species," states that, "Aside from KU 2357 [a specimen from ‘Southern Oklahoma,’ described as a single ‘soft, dark colored male having 129 ventrals’ in the collection of the University of Kansas], no other smooth green snakes have been discovered in Oklahoma." – TEL]
 Werler, J. E., ed. 1962. Texas Herpetological Society News Letter (March, 1962, mimeo.), p. 1-13. [Under "news and notes," page 4, Werler describes finding large concentrations of snakes on high ground near Angleton, TX, as a result of flooding associated with Hurricane Carla the previous fall. Among them were three (?) Opheodrys vernalis. – TEL]

Werler, J.E. and J.R. Dixon. 2000. Texas Snakes. Identification, distribution, and natural history.  Austin: University of Texas Press.  [In their magnum opus on the snakes of Texas, Werler and Dixon (2000) added very little information to that contained in the newsletter 38 years earlier:

"Most smooth green snakes found in Texas were discovered during late April and early June, usually following rain showers.  An opportune time to find these elusive snakes is immediately after a hurricane or severe storm, when the rising waters have inundated the low-lying coastal prairies, forcing many of the local terrestrial snakes from their hiding places.  It was after such a hurricane that two smooth green snakes were discovered near Angleton, crawling over clumps of grass on one of the few available spits of high ground." (Werler and Dixon 2000). 

Unexplained is how the number of snakes taken changed from three in the original newsletter report into two in the subsequent account.  Regardless, given the stature of John Werler, plus the fact that I personally saw one of the preserved specimens, I accept this sketchy evidence as valid, especially so considering how few Texas records exist.  - TEL]
Worthington, R. D. 1973. Remarks on the distribution of the smooth green snake, Opheodrys vernalis blanchardi Grobman, in Texas. Southwest Nat. 18(3): 344-46.

Wright, A. H., and A. A. Wright. 1952. List of the snakes of the United States and Canada by states and provinces. Am. Midl. Nat. 48(3): 574-603.

Wright, A. H., and A. A. Wright. 1957. Handbook of snakes of the United States and Canada. Ithaca, N. Y.: Comstock Publishing Co. ["The very puzzling records from Texas have been generally discredited. Strecker (Tex., 1915) summarized thus: ‘The smooth-scaled green snake has been reported from only two widely separated localities, i.e., Washburn, Armstrong County (Bailey), and Deming’s Bridge, Matagorda County (Garman).’ Recently Davis has given a different aspect to this question: ‘the status of Opheodrys vernalis in Texas is again brought to attention by the capture of a male specimen 2 1/2 miles west of Sealey, Austin County, on Apr. 23, 1949. . . . Because of this recent capture of vernalis, I am inclined to accept the records from Basque [sic, error is in the Wrights’ transcription as Davis’ note has the correct spelling, Bosque], Ellis and Matagorda counties as authentic.’" "Letter from Kirn, Somerset, Tex., May 6, 1946: ‘Did I ever tell you that there are two smooth-scaled snakes, Opheodrys v. blanchardi (?) in the collection at St. Mary’s Univ., San Antonio? They are from the Marnock collection, and the jar is labeled "Green snakes, Helotes." There is no label on the specimens.’" – TEL]

Yarrow, H. C. 1883. Checklist of North American Reptilia and Batrachia with catalogue of specimens in the U.S. National Museum. Bull. U.S. Natl. Mus. 24: 1-249.  [Included a listing of a female specimen from "Owassee," Texas (now USNM 1489), which does not appear to be a valid locality in the state.  Consequently, this specimen, although it is truly an O. vernalis, likely does not represent an early record for the state. - TEL]