bluuebunny/crossref_metadata_2025_split huggingface dataset:
CHROMOSOME NUMBERS AND RELATIONSHIPS IN ANNONIFLORAE
Authors: Raven Peter H. , Kyhos Donald W. , Cave Marion S. 
Published: April 2006

SummaryFirst reports of chromosome numbers in the following families of Annoniflorae, suborder Laurineae, are presented: Gomortegaceae (Gomortega nitida, 2n = 24), Gyrocarpaceae (Gyrocarpus americanus, n = 15), and Lactoridaceae (Lactoris fernandeziana, 2n = c. 40). For Monimiaceae, the most important basic number for subfamily Monimioideae is x = 19, while other numbers must be confirmed. The recently segregated Siparunaceae and Atherospermataceae have x = 22. Further chromosomal work in Monimiaceae s. lat. is strongly urged.
TERMINOLOGY OF HAIRS IN THE GENUS SOLANUM
Authors: Roe Keith E. 
Published: April 2006

SummaryThe taxonomic value of plant hairs would be enhanced by a standardized terminology. However, the great diversity in hair morphology often precludes using single terms to describe hair types. In some genera the multitude of hair features requires numerous descriptive terms just as do other complex plant parts. It is suggested that efforts be made by systematists using hair characters in descriptions to be precise in terminology and to derive terms from Latin rather than generalize hair types as simple, stellate, etc. The genus Solanum exhibits great hair diversity. Some examples of hairs from this genus are illustrated and a terminology suggested.
TOWARD A RATIONAL CLASSIFICATION OF CULTIVATED PLANTS
Authors: Harlan J. R. , de Wet J. M. J. 
Published: April 2006

SummaryThe methods of formal taxonomy have not been very satisfactory for the classification of cultivated plants. As a result, the people who deal with cultivated plants the most have developed their own informal and intuitive classifications based on experience as to what constitutes useful groupings. An attempt is made to provide a framework in which both systems can operate with a minimum of confusion. The structure of the total available gene pool is characterized by assigning taxa to primary, secondary and tertiary gene pools. At the infraspecific level, cultivars are grouped into races and subraces in an informal way without rigid rules for the use of terms.
A NEW ALGAL CLASS — THE EUSTIGMATOPHYCEAE
Authors: Hibberd D. J. , Leedale G. F. 
Published: April 2006

SummaryA formal description is given of a new class of algae, separated from the Xanthophyceae by several unique features of zoospore organisation, particularly the large size and special construction of the eyespot and the location of the flagellar swelling, and the form of the pyrenoid in the vegetative cell.
EFFECTS OF PREPARATION TECHNIQUE ON POLLEN PREPARED FOR SEM OBSERVATIONS
Authors: Hanks Sharon , Fairbrothers David E. 
Published: April 2006

SummaryPollen grains of taxa representing the four described pollen types of Fagus and Nothofagus were observed with the scanning electron microscope to determine preparation effects. Pollen grains were observed before treatment with KOH, after treatment with KOH, and after acetolysis had been completed. The photomicrographs illustrate that the effect of various preparation techniques differ from species to species. Therefore, it is important in any systematic pollen research to ascertain the amount of change in the material so that the data can be placed in proper perspective for comparative interpretation.
CO‐EVOLUTION OF PLANTS AND ANIMALS — SYSTEMATIC INSIGHTS FROM PLANT‐INSECT INTERACTIONS
Authors: Macior Lazarus Walter 
Published: April 2006

SummaryBorn over 200 years ago the science of anthecology (pollination ecology) has developed new concepts in the last 50 years using quantified information from studies of insect sense perception and behavior. Flower‐insect coadaptation is considered a continuing process in which changing interrelationships establish and remove reproductive barriers in breeding systems at the vital link of pollen transport. Convergent evolution is apparently reflected in the development of similar pollination mechanisms in unrelated plant taxa through pollinator sharing, floral mimicry, and synchronous anthesis of sympatric species. Reproductive isolation of plant taxa is suggested in diversity and versatility of pollinator behavior, unsynchronized anthesis, and functional as well as structural differences in pollination mechanisms. Contributions of anthecology to systematics are primarily useful for a fuller understanding of the origin of taxonomic entities and secondarily in defining criteria for their establishment.
THE ORIGIN OF REPRODUCTIVE ISOLATING MECHANISMS IN FLOWERING PLANTS
Authors: Levin Donald A. 
Published: April 2006

SummarySympatric congeneric species of flowering plants are precluded from freely exchanging genes by reproductive barriers which are operative prior to pollination, between pollination and fertilization and after fertilization. The barriers may be the by‐products of divergent evolution, or may have been selected for their ability to reduce hybridization and disruptive gene flow, or competition for similar elements of the pollinator fauna. Autogamy and hybrid floral isolation are included in a classification of reproductive isolating barriers. The origin of reproductive barriers is discussed in light of new information and insight on pollinator behavior and perception, the S‐gene complex, pollen‐tube competition, and population level selection. It is suggested that reproductive barriers are not inherent properties of species, but reside in the interface between species, and arise from the incongruities in the reproductive formats of species paired in nature or by the systematist.
PROBLEMS OF ANTIPODAL DISTRIBUTION IN LOWER LAND PLANTS
Authors: Schuster Rudolf M. 
Published: April 2006

SummaryThe geographical distribution of the more primitive Hepaticae (subclass Jungermanniae) exhibits the same patterns of endemism and disjunction, and highly specific and restricted ranges as found in many groups of vascular plants. The subantarctic region is shown to have an unduly high preponderance of primitive genera present (ca. 50% of all known unspecialized types), of which very many are strictly endemic there. Many of these groups are cold‐adapted types which seem to have exhibited only limited displacement northward as a result of late‐Tertiary and Pleistocene deterioration of the climate; others (Blepharostomataceae) have shown some striking dispersal to the cold regions at the opposite side of the globe, but the bulk of taxa remain Antipodal. Other families (Gymnomitriaceae, Scapaniaceae) that seem to lack tolerance for warm climates are today very preponderantly Arctic subarctic (and Alpinesubalpine), but the most primitive taxa are still strictly subantarctic, leading to the conclusion that these largely Holarctic families are originally Panantarctic. From the evidence given it is concluded that many but probably not all major groups of the Jungermanniae may have originated in this Panantarctica (Gondwanaland). The recent overwhelmingly “in phase” data corroborating the theory of continental drift, plus the relatively late times for separation of the Australian‐Tasmanian‐New Zealand area from Antarctica (ca. 40‐60 m.y. ago; perhaps somewhat earlier in the case of New Zealand) suggest much of the dispersal (of older, unisexual taxa) may have been overland during late Mesozoic and early Tertiary times. Ranges of some taxa on islands near or on the Mid‐Atlantic and Indian‐Ocean ridges, islands which vary from 1‐20 million years in age, clearly indicate some taxa (especially bisexual ones) may have wider powers of spore‐dispersal than sometimes assumed. Present evidence does not, often, allow us to distinguish between ancient “overland” dispersal, and more recent dispersal via spores.
II. IMPLICATIONS AND EXTENSIONS OF THE SERIAL ENDOSYMBIOSIS THEORY OF THE ORIGIN OF EUKARYOTES
Authors: Taylor F. J. R. 
Published: April 2006

SummaryIn comparison to other theories put forward so far, the Serial Endosymbiosis Theory appears to be the most critically favoured as an explanation for the origin of mitochondria and chloroplasts. For this reason some of its implications are drawn attention to. In particular it is shown that present hierarchical concepts and terminology based on the classical cell theory are inadequate to cope with the S.E.T. (as the theory is abbreviated here). It is shown that the topological relations of mitochondria and chloroplasts to the cell suggest that they are topologically “outside” it, “embraced” rather than lying truly within it. This position is consistent with the S.E.T. On the other hand microtubule‐organising‐centres are truly within the cell. An autogenous origin for the latter seems to be more likely than the endosymbiotic proposal of Margulis.In addition to the primary origin of organelles by the transformation of entire prokaryotic endosymbionts, the possibility of the maintenance of eukaryotic organelles produced by one cell, taken into another, is discussed. Examples of some recently discovered, unusual photosynthetic states in ciliates, brought about by temporary foreign chloroplast maintenance, and possibly degeneration of endosymbiotic photosynthetic flagellates, are discussed in this context. The existence of some contemporary examples of photosynthetic bodies which seem to be intermediate between endosymbiotic blue‐green algae and chloroplasts, suggests that some organelles may have had a more recent origin than the Precambrian Era, the process being a continuous one.Some of the difficulties inherent in alternative theories for the origin of eukaryotes are discussed. It is stressed that alternative proposals have not yet received intensive exposition and comparisons with the S.E.T. are thus difficult. Attempts to use single criteria (particularly biochemical) as phylogenetic “markers” should be made with due consideration of the S.E.T.Finally, it has bearing on the recognition of kingdoms, for it widens the already acknowledged chasm between prokaryotes and eukaryotes, intermediates between the two types of organisation being impossible (as stressed by Margulis).
PHYLOGENY OF PROCARYOTES
Authors: De Ley J. 
Published: April 2006

SummaryWe first list the main experimental methods used to get an insight into the phylogenetic relationships of the presently existing bacterial genera. Their scope and relative merits are briefly discussed.As a model system we briefly summarize the application of most of those methods to elucidate the phylogenetic relationships within the genus Agrobacterium. The evolutionary development of this genus is described.Similar experiments with Zymomonas are summarized.
DISJUNCT DISTRIBUTIONS IN THE NEW WORLD ZYGOPHYLLACEAE
Authors: Porter Duncan M. 
Published: April 2006

SummaryThe disjunction of the genus Larrea between the arid regions of North and South America is well known and much discussed in the phytogeographical literature. Not so well known are the North American‐South American disjunctions in Fagonia and Porlieria, the New World‐Old World disjunctions in Fagonia and Peganum, and Bulnesia's disjunction within South America. Each genus, its close relatives in the family, and possible explanations for its present distribution are discussed.
NAMES FOR THE CULTIVATED CAPSICUM SPECIES (SOLANACEAE)
Authors: Heiser Charles B. , Pickersgill Barbara 
Published: April 2006

SummaryRecent taxonomic treatments of the cultivated species of Capsicum are discussed and divergent opinions on the names to be employed for some of these demonstrated. It is concluded that five species are widely cultivated and that the correct names for these are C. pubescens R. & P., C. annuum L., C. baccatum L., C. frutescens L., and C. chinense Jacq.
THE SPECIES CONCEPT IN QUERCUS
Authors: Burger William C. 
Published: April 2006

SummaryThe modern biological species‐concept, defined by genetic isolation, describes a phyletically independent system of populations. Most of the species‐concepts in everyday use for the oaks (Quercus) exhibit genetic interchange with other so‐called species. Nevertheless, these classical concepts remain in use and represent biologically meaningful populations. In addition, it is suggested that the classical species of Quercus may represent phyletic units in species‐grade evolutionary advances. A comparison between the biological species‐concept and the classical species‐concept in Quercus suggests why the classical concepts have been retained. The biological species‐concept appears to be a population system of extraordinary complexity and difficult to delimit in Quercus. This genetically isolated complex population system is not directly comparable to genetically discrete species in most other genera. The prime function of the species binomial is as a unit of communication. The biological species‐concept must be used with greater flexibility as regards taxonomic rank if its designation by means of a binomial cannot provide a functional information retrieval system.
ON THE TAXONOMY AND TYPIFICATION OF MUSCARI MILLER (LILIACEAE) AND ALLIED GENERA, AND ON THE TYPIFICATION OF GENERIC NAMES
Authors: Garbari F. , Greuter W. 
Published: April 2006

SummaryThe types of the names of taxa above the rank of species cannot, logically, be taxa (species, etc.) but only names of taxa (in the sense of the ‘Code’). Accordingly, the type of the name Muscari Miller is the name Muscari botryoides (L.) Miller, as proposed by Britton and Brown in 1913, and is considered to be a neotype.The species currently included in Muscari belong to 4 distinct genera (one of which is new) with 3 additional sections. Full synonymies and latin diagnoses of all these taxa are given. The name Leopoldia Parl. 1845 (non Herb. 1821) is proposed for conservation.
SYSTEMATIC ANATOMY OF THE LEAF EPIDERMIS IN THE MAGNOLIACEAE AND SOME RELATED FAMILIES
Authors: Baranova Margarita 
Published: April 2006

SummaryStomatal and other epidermal features suggest a close relationship among the Magnoliaceae, Eupomatiaceae, Degeneriaceae, and Himantandraceae, a somewhat more distant relationship of the Winteraceae to these families, and only a much more distant relationship of the Illiciaceae and Trochodendraceae to this group. Epidermal characteristics of the various genera and species of the Magnoliaceae are highly compatible with the taxonomic scheme of Dandy, and in some respects give strong support to it. The generic separation of Manglietia from Magnolia is particularly supported by my studies. Within the Winteraceae, epidermal features of several species of Belliolum correlate well with the system of A. C. Smith for this genus. The species Bubbia perrieri is anomalous in Bubbia on epidermal features, though clearly a member of the Winteraceae; its taxonomic position merits reconsideration. Many members of the Magnoliales have thickened lamellae (distinct from the outer stomatal ledge) on the outer walls of the guard cells, similar (except in not being lignified) to such lamellae in the modern Cycadales. The presence of these lamellae is considered to be a primitive feature among the angiosperms. Thick‐walled epidermal cells with pores in the outer wall are found in many of the Magnoliales, and this feature is also considered to be primitive within the angiosperms. It is noteworthy that the Cycadales also have thick‐walled cells, and that in Cycas and some other genera these cells have pores in the outer walls. The vast majority of the Magnoliales have paracytic stomates, and this is considered to be the primitive type within the angiosperms.
CHARACTERS AND CLUSTERING IN TAXONOMY: A SYNTHESIS OF TWO TAXIMETRIC PROCEDURES
Authors: Legendre Pierre , Rogers David J. 
Published: April 2006

SummaryThe problem of producing a classification from data gathered on specimens has two main components: first the information about the specimens must be structured as characters and character states in such a way that it carries the most information about the taxonomic structure of the objects under study, the mathematical ‘noise’ being eliminated as much as possible. Then this information must be handled in such a way that a hierarchical partitioning of the objects, called classification, is derived.This paper presents computer‐aided methods for the accomplishment of these steps. These methods were worked out to be both mathematically and biologically sound. The character analysis method (called CHARANAL) uses information theory to measure the amount of information common to pairs of characters, and derives from it various measures for the comparison of characters. The clustering technique presented here (entitled GRAPH), on the other hand, is based upon graph theory, and is intended to represent the thought process of the ‘classical’ taxonomist. For each method are given a general explanation, a detailed explanation of the mathematics involved, an example, and a section on interpretation of results.
LECTOTYPIFICATIONS OF SOME GENERIC NAMES OF GESNERIACEAE
Authors: Morton C. V. , Denham Dale 
Published: April 2006

SummaryWe have been looking up the original publication of all the generic names of the family Gesneriaceae for the Index Nominum Genericorum. Dr. B. L. Burtt has in various publications chosen lectotypes for many of the Old World genera, but many of the New World ones have not as yet been properly lectotypified. Generally, the proper lectotype is obvious, even though it has not been formally designated, and these we have chosen here. There are only a few names, like Diplocalyx K. B. Presl (still wholly dubious), Orobanchia Vandelli (also dubious), and Gesnera Mart. (non L.) that must remain ‘provisional’ for the time being.
ECOLOGICAL SPECIES, MULTISPECIES, AND OAKS
Authors: Van Valen Leigh 
Published: April 2006

SummaryOaks exemplify problems with the reproductive species concept which motivate a reconsideration of the use and nature of species. Ecology is important in the reconsideration. The species level is usually overemphasized in evolutionary thought; selection acts on phenotypes and any mutualistic units. Standard definitions tend to inhibit free conceptual progress. Multispecies, sets of broadly sympatric species that exchange genes, may occur among animals as well as plants and may conceivably bridge kingdoms. This phenomenon can be adaptively important. There may be taxa without species. The degree of modality of adaptive zones can be investigated empirically.
A DISTANCE COEFFICIENT AS A HYBRIDIZATION INDEX: AN EXAMPLE USING MIMULUS LONGIFLORUS AND M. FLEMINGII (SCROPHULARIACEAE) FROM SANTA CRUZ ISLAND, CALIFORNIA
Authors: Wells Harrington 
Published: April 2006

SummaryIn studies where hybridization is suspected, data frequently are presented as Anderson pictorialized scatter diagrams and Anderson hybrid indices. These two techniques, however, introduce inherent biases which influence the reader's interpretation of the data. In this article a new method based on a euclidean distance coefficient is suggested as a replacement for both the pictorialized scatter diagram and hybrid index. It is as simple to perform as the Andersonian techniques but relatively free of biases. Morphological data on Mimulus longiflorus and M. flemingii from Santa Cruz Island, California, were gathered to illustrate the new index of hybridization and to show its advantages over the traditional Anderson pictorialized scatter diagram and hybrid index. Model examples are also used to compare these techniques of data analysis.
NUMERICAL ANALYSIS OF VARIATION BETWEEN ALLIUM CERNUUM AND ALLIUM STELLATUM (LILIACEAE)
Authors: Jacobsen T. D. 
Published: April 2006

SummaryVariability within and between two species of closely related onions (Allium cernuum Roth and Allium stellatum Wats.) was measured using methods of cluster and principal component analysis. These two widely distributed but overlapping species are sometimes difficult to distinguish. Analysis with 62 characters supports the classification of the two as distinct taxa. The level of dissimilarity between the two taxa falls within the range of interspecies dissimilarity for the genus.
WAGNER NETWORKS AND WAGNER TREES: A PRESENTATION OF METHODS FOR ESTIMATING MOST PARSIMONIOUS SOLUTIONS
Authors: Jensen Richard J. 
Published: April 2006

SummaryThe methods of Wagner network and Wagner tree construction are presented. A worked example, based on a set of hypothetical taxa, is examined in detail. Additional examples, representing real and artificial data sets, are also examined. The existence of alternative choices at several stages in the algorithms leads to solutions that may not be most parsimonious estimates. There apparently is no non‐arbitrary method for choosing between the alternatives. The examples presented illustrate that there may be multiple equally parsimonious solutions for a given data set and that neither algorithm can ensure a most parsimonious solution.
A PRELIMINARY NUMERICAL ANALYSIS OF THE RED OAK COMPLEX IN MICHIGAN AND WISCONSIN
Authors: Jensen Richard J. 
Published: April 2006

SummaryIndividuals representing five taxa and numerous unidentified OTU's of red oaks native to the western Great Lakes region of the United States were examined through principal components analysis. Two data sets, one consisting of twenty untransformed characters and one in which various characters were redefined as ratios, were employed for comparative analyses. Although minor differences are noted, the two data sets provide essentially the same view of the relationships between the included OTU's. The five taxa appear to form more or less discrete groups with the unidentified OTU's occupying positions of intermediacy. The results support previous conclusions that extensive hybridization occurs among the red oaks of this geographic region.
THE DISTRIBUTION OF STORAGE PROTEINS IN MAGNOLIOPHYTINA (ANGIOSPERMS) AND THEIR SEROLOGICAL SIMILARITIES
Authors: Jensen Uwe , Büttner Christa 
Published: April 2006

SummaryIn this research we have demonstrated that the storage proteins, Aquilegilin and Tubiflorin, occur in nearly all taxa of the Magnoliophytina (angiosperm) families tested. Jensen and Penner (1980) have reported the value of comparing partially purified seed storage proteins extracted for plant taxonomic research. Büttner and Jensen (1981) established the homology of seed storage proteins isolated from Aquilegia vulgaris and Digitalis purpurea. The different amounts of serological reactivity detected among various plant taxa have been interpreted as being a reflection of evolutionary differences in the primary structure of the protein. While the serological differences were great between taxa of different families, taxa of different genera within each family usually were distinguishable only when the reference systems (antisystems) had been obtained from the same family. However, proteins obtained from species within a single genus were difficult to distinguish. The serological experiments comparing the proteins from different Magnoliophytina (angiosperm) families (Fig. 4), generally reflect the relationships of the tested families with the Ranunculaceae and the Scrophulariaceae as reference families.ZusammenfassungWährend Jensen and Penner (1980) bereits den vergleichenden Einsatz von isolierten Samen‐Reserveproteinen in der Verwandtschaftsforschung als sinnvoll erkannt hatten, konnten Büttner and Jensen (1981) auf die Homologie von in Aquilegia vulgaris und Digitalis purpurea ‐ Samen enthaltenen Reserveproteinen hinweisen. Jetzt zeigte sich, daß die Reserveproteine Aquilegilin und Tubiflorin in den Vertretern fast aller getesteter Angiospermenfamilien vorkommen. Ihre abgestufte serologische Reaktivität deutet auf evolutive Veränderungen der Primärstruktur hin. Während die serologischen Unterschiede bei Vertretern verschiedener Familien beträchtlich sind, sind Vertreter verschiedener Gattungen einer Familie oft nur mit Hilfe von Bezugssystemen (Antisystemen) aus dieser Familie differenzierbar. Die benutzten Reserveproteine aus Arten einer Gattung schließlich sind nur schwer unterscheidbar. Die serologischen Vergleiche der beiden Proteine aus einer Reihe von Angiospermenfamilien führten zu einem Bild (Fig. 4), das die abgestuften Verwandtschaftsverhältnisse in Bezug auf die Ranunculaceen und Scrophulariaceen im allgemeinen widerspiegelt.