Names
Common and scientific
names of organisms were gleaned from many sources, including the vegetation
references given immediately above. Most plant names came from the various manuals
or flora of the regions (eg. Great Plains Flora Association, 1986; Looman and
Best, 1987), states (eg. Steyermark, 1963; Correll and Johnston, 1979; Munz
and Keck, 1973; Hickman, 1993); and parts of states (eg. Diggs et al., 1999).
Names of genera and species within such sources are in some state of disarray
these references being of various publication ages and there being no comprehensive,
encyclopedic authority for the nomenclature of the North American flora.
Selection of names was basically conservative and traditional with the intent being to use those names that appeared more frequently over the time frame covering the major works on range vegetation by the leading authorities. The objective was to aid the reader in knowing the plants and, sometimes, animals in the landscapes being viewed and to facilitate comparison with descriptions of the vegetation in the classic literature, much of which is over a half century old. It was not the objective to automatically use the most recent or the current binomial asserted to be the “correct” one by some herbarium-corralled, type-specimened botanist claiming that such-and-such is really the “right” name while the one used for the last 60 years is “wrong”. Names of extended usage in the literature were chosen over radically new and different names that were absent from the major works. For example, the needlegrasses were shown by the long-standing generic name of Stipa; Achnatherum, Hesperostipa, and Nassella were all resoundingly rejected.
When the first three copyright editions of this web publication were presented the following clarifying statement was included: "Many of the grass names were those given by Hitchock and Chase (1950) which after 50 years is still the only encyclopedia for Gramineae in the United States. (Nor is it likely that confusion will be ended and taxonomic precision improved if and when this standard is replaced.)". Subsequently such an encyclopedia--and a monumental work of agrostological scholarship by a cadre of experts--was concluded and promptly made available. In 2003 Volume 25 of the Flora of North America North of Mexico, devoted to eragrostoid and panicoid grasses, was published (Barkworth et al., 2003). Volume 25 was followed four years later by Volume 24 which covered the remaining festucoid, arundinoid, bambusoid, etc. grasses (Barkworth et al., 2007). These two marvelous volumes were the result of hard work and devotion by almost countless dedicated individuals and and numerous institutions.
Unfortunately the second sentence in the above quote from Range Types was prophetic: Confusion was not ended and although taxonomic precision was, hopefully, improved the new "grass encyclopedia" acknowledged that classification of or within certain tribes and genera of Poaceae was "controversial" while delimitation of some taxa was "not yet clear". Obviously science is ever-changing even as the asympote toward perfection in grass classification proceeds. Nonetheless, the author of Range Types stood by his earlier conclusions and opinions with regard to confusion and controversy in grass taxonomy. This author tersely commented that when agrostologists can clear out the moth ball vapors long enough to decide if western wheatgrass is in genus Elytrigia or Pascopyrum (or a third or fourth candidate) Agropyron smithii could be safely superceded. Pascopyrum smithii was settled on in the grass encyclopedia of Flora of North America (Barkworth et al., 2007, ps. 350-351) based on published conclusions derived from genomic analysis. The situation remained however that the classic and comprehensive descriptions of North American range vegetation had used Agropyron smithii in most of the authoritative and historic literature, including the definitive North American Terrestrial Vegetation (Sims in Barbour and Billings, 1988, p. 275, 277) until the last decade or two during which time accepted binomials for western wheatgrass were Elytrigia smithii (eg. Hatch and Pluhar, 1993, ps. 174-175) or Elymus smithii with the latter including use in major revised florae such as Steyermark's Flora of Missouri (Yatskievych, 1999, p. 875) as well as in scholarly field guides (eg. Tyrl et al., 2002, p. 81). Eventually Pascopyrum smithii began to see common but, by no means, exclusive usage (eg. Hickman, 1993, p. 1280; Jones et al., 1997,254; Sims, in Barbour and Billings, 2000, p. 337, 339). Simply put, nomenclature of native plants, particularly North American grasses and grasslike plants, has been (and appears to still be) in turmoil. Finally, it is a fact that most of the descriptions of rangeland and forest plant communities (ie. the qualitative ecological studies of range vegetation) were done decades ago so that replacement of the then-accepted or the traditional, historic species names by newer scientific names (nomenclature based more on genetics than morphology) would introduce a major source of confusion.
Conversely, retention of older, longer-used binomials that exists in the classic qualitative ecological literature still permits cross-referencing of these historic names with newer binomials (and names of other taxa such as tribes or subfamilies as in the Gramineae= Poaceae) in published synonymies (eg. Barkworth et al., 2007, ps. 831-875). This seemed the simplier and less confusing approach (at least to this author) given that scientific names in existing literature will not change while taxonomic names are bound to change in future literature.
For some species more than one widely accepted binomial existed in current manuals so synonyms were given as, for instance, with little bluestem (Andropogon scoparius= Schizachyrium scoparium). To expedite reading of names authorities were not listed behind the specific epithet. Authors can be found in the various flora. The convention of using the scientific binomial only once in the text immediately following first appearance of common name was generally followed.
In regards scientificf names (and ecological terms and theories) "what goes around comes around". This truth of this time-proven axiom was illustrated at several junctures in the following publication. Many of the scientific names have been changed back-and-forth, some several times. Readers can follow this taxonomists' fashion show (ie. the "publish or perish" racket equivalent to the designer industry ups-and-downs of hemlines and widths of neck ties) by purusing the manuals and peer-reviewed journals.
Welsh (in Welsh et al., 1993, p. v) accurately explained this situation: "More modern workers clog the system with endless generic name substituions, a kind of endless one-up-man-ship which serves to get their names in print, but does not add much if anything to the understanding of plant taxonomy". The above mentioned case of the traditional genus, Stipa, and acceptance or rejection of what the current author regarded as flippant treatments by "modern workers" was illustrated by the flollowing assessment of L.A. Arnow (also in Welsh et al., 1993, p.875): "The treatment of Stipa was reviewed by M.E. Barkworth prior to the publication of the first edition of A Utah Flora. Recent nomenclatural proposals by her (1993) are not followed herein. Tradition in plant taxonomy shoud count considerably in any decision to transfer species wholesale, especially where such species groups hybridize as freely as between some of the segregates as proposed by Barkworth (1993)".
Hybridization presents another problem to contemporary nomenclature and modern phylogenetic classification, which is regarded by many ( (though certainly not by all) as synonymous with cladistics. Some taxonomists interpret natural hybridization as a major basis for allocating species to this or that genus. For example, Barkworth et al. (2007, ps. 445-448) reinterpreted tall fescue (Festuca arundinacea) as a member of Schedonorus (S. arundinaceus) with Schedonorus being more closely affilitated with Lolium than with traditional treatment as Festuca. All of these genera, of course, were still regarded as members of tribe Festuceae or Poeae.. Almost two decades earlier Stace (1989, ps. 146-147) opposed various proposals to amalgamate and/or split Festuca, Lolium, and Vulpia on basis of natural hybridization arguing that such rearrangements ignored the fact that some interspecies hybrids are fertile and "that natural hybridization does not present the complete picture". Crosses between two plant species does not always result in sterility (infertile progeny). There is not always a a barrier to gene exchange between species becausesometimes interspecific pollination does lead to fertile offspring. This means that sexual reproduction is not always--or even usually--a reliable criterion on which to separate species (or even genera).
In final analysis, nomenclature and phylogeny as given by Barkworth et al. (2003, 2007) may be "official", but that does not mean that it was (is) by any means universally accepted by agrostologists and other taxonomists nor that treatments therein are taxonomically correct. This entire argument essentially comes down to whether or not one accepts cladistics as the basis for taxonomy and nomemclature of plants. The author of Range Types of North America rejected cladistics and its basic reqirement of recognizing only monophyletic groups. As such, scientific names such as newer genera split out from the traditional genera such as Stipa, Festuca, and Elymus were not accepted by this author and were usually not included as synonyms in Range Types. Readers wishing objective and thorough discussion of the cladistics controversy were referred to Appendix Six in Diggs et al. (1999, ps. 1372-1378). The author of Range Types felt strongly that it was most regreatable that the only encyclopedia of the North American Gramineae, complete with its extraordinary line drawings, (Barkworth et al., 2003; Barkworth et al., 2007) and that was so strongly supported by numerous individuals and institutions and amased through the labor of some of the greatest taxonomists based conclusions on cladistics rather than the admittedly more subjective phyletic approach such as the "new phyletics" proposed by Stuessy (1990, ps. 142-153; 2009, ps. 117-127). Stace (1989, p. 63) concluded that use of cladistics will often improve plant classification and cladistic methods will always improve collection and manipulation of data, "[b]ut dogmatic insistence that the cladistic approach is always the best one, or the only valid one, will greatly hinder progress".
Taxonomy, habit, natural history, and other standard details of individual plant species (or other botanic taxa) were not presented in this publication because it was devoted to vegetation and not plants per se. This publication was not intended to be-- indeed given that the publication was of range types and not range plants, it was deemed inappropriate to even attempt to be-- an authoritative treatment of the taxonomy and basic biology of individual species. There are countless field guides, "wild flower books", seed company pamphlets, and government agency papers devoted to the various range and forest plant species. These are in addition to the flora and manuals already mentioned. There are even web publications devoted to the plants of various range regions. One of these was given in the Useful Links section of this web publication.
Some specific details of morphological features, systematic/taxonomic characters, and practical biological aspects of certain species were mentioned (sometimes given considerable discussion) when the same were: 1) essential to understanding composition, structure, and function of vegetation, 2) directly related to on-the-ground management of rangeland and forest cover types, or 3) central to explaining why specific species were dominants, associates, indicator plants, or noxious range plants. Length of life cycle, toxic aspects (poisonous plant principles), status of naturalized or ruderal, morphological features related to palatability and forage/browse value, tolerance of forest species, dispersal characteristics, and relative importance of asexual versus sexual reproductive were some of the more obvious examples of such details.