Showing papers in "Taxon in 1987"
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TL;DR: The genera of the Eupatorieae (Asteraceae) are characterized by their high diversity and high ability to tolerate high temperatures.
Abstract: The genera of the Eupatorieae (Asteraceae) , The genera of the Eupatorieae (Asteraceae) , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
194 citations
TL;DR: Methods for shape comparisons among groups originally developed in zoological studies are found to be useful in examining variation in leaf shape and with respect to a search for possible leaf shape intermediacy in putative Crataegus hybrids, and an examination of geographic variation in the cross-sectional shape of Larix laricina needles.
Abstract: Summary Methods for shape comparisons among groups originally developed in zoological studies are found to be useful in examining variation in leaf shape. These methods (sampling outlines by means of truss networks connecting landmarks or pseudolandmarks, and sheared principal components analysis) take advantage of electronic methods of data capture and multivariate data analysis. They have the desirable properties of discriminating between shape variation and variation in size, and of permitting their results to be related directly to the original measurements from which they were obtained. The utility of these methods is demonstrated with respect to a search for possible leaf shape intermediacy in putative Crataegus hybrids, and an examination of geographic variation in the cross-sectional shape of Larix laricina needles.
TL;DR: This volume explores the limitations of the present systems of classification, and considers the development of more workable systems in the future.
Abstract: The classification of plants at infraspecific level is often difficult - variation can be continuous, making a traditional hierarchical classification difficult to maintain. In particular, cultivated plants may require special artificial systems of classification, to conform to the practical needs of breeders. This volume explores the limitations of the present systems, and considers the development of more workable systems in the future.
TL;DR: It is proposed that trimery is a morphological constraint, which offers only very limited possibilities for meristic variation, with no return to pentamery or spiral anthotaxy possible.
Abstract: Summary The purpose of this note is to bring into focus the morphological and evolutionary relationship between spiral anthotaxy and pentamerous, trimerous and dimerous whorls. The trimerous as well as the pentamerous condition has its morphological and evolutionary origin in spiral anthotaxy, and slight morphogenetic changes are responsible for the switch from spiral to whorled anthotaxy, the latter including pentamery, trimery, and rarely dimery. A pentamerous whorl is considered to be morphologically equivalent to two alternating trimerous or dimerous whorls. The transition from spiral to whorled anthotaxy is documented in several extant families of the Ranalean complex and must have taken place in parallel in various-albeit related-evolutionary lines. Except for its predominance in the monocotyledons and frequent occurrence in the Ranalean families trimery is relatively rare in other dicotyledons, and its morphogenetic origin may be different in these two major groups. It is proposed that trimery is a morphological constraint, which offers only very limited possibilities for meristic variation, with no return to pentamery or spiral anthotaxy possible. 1. Statement of the Problem Trimerous flowers are one of the unifying traits of the monocotyledons. In the few cases where they are absent in this group hypotheses exist that attempt to relate quite convincingly simpler flower structures to the trimerous ground plan. Trimerous flowers are also encountered, although less regularly so, in many families of the Magnoliales s.l. (including Laurales), Ranunculales and Piperales. In the dicotyledons they are often accompanied by features that are predominantly monocotyledonous. Many authors, starting with Lotsy (1911) and Suessenguth (1921), have thus been led to assume close ties between the Ranalean families and the monocotyledons. Huber (1977, 1982) has shown that the gap between the monocotyledons and dicotyledons is far less clear cut than commonly believed and has gone so far as to view the most significant cleft among the angiosperms, not between the two conventional classes monocotyledons and dicotyledons, but between the Ranalean assembly together with monocotyledons and Centrospermae ("first principal group" of Huber, 1982) on the one hand, and the rest of the dicotyledons ("second principal group") on the other. Kubitzki and Gottlieb (1984) have adduced phytochemical evidence in support of this division. What remains debatable is a proper understanding of the evolutionary origin and systematic significance of trimerous flowers. Different opinions about their evolutionary origin have been offered more recently. Based on the distribution of trimerous flowers and their correlation with other characters Dahlgren (1983) concludes that this trait must be ancient and must have "appeared in angiosperms before the differentiation of the monocotyledons, i.e. at least in Albian times" and that trimerous flowers "presumably occurred side by side with flowers with helically arranged parts." After pointing to the frequent occurrence of trimerous flowers in the Ranunculales, Dahlgren (1983) continues: "It is likely that the pentamerous state has evolved out of a trimerous in this order, perhaps several times, an
TL;DR: This phylogeny describes the evolution and phylogeny of the families of Monocotyledons using data from the fossil records of E.coli, Yersinia, and Tournaisia as well as new fossil records from China.
Abstract: Classification, evolution, and phylogeny of the families of Monocotyledons , Classification, evolution, and phylogeny of the families of Monocotyledons , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
TL;DR: The Ferns to Grow encyclopedia as discussed by the authors is an encyclopedia of botany, cultivation, propagation, and pests and diseases of ferns and includes growing information for hundreds of species.
Abstract: This encyclopedia is really two books: the first is a guide to the botany, cultivation, propagation, and pests and diseases of ferns; and the second half, Ferns to Grow, provides growing information for hundreds of species.
TL;DR: The genus Stylosanthes Swartz is one of the central foci of research into the improvement of tropical pastures and has a number of critical specific and subspecific taxa, some of which are listed below.
Abstract: Introduction The genus Stylosanthes Swartz (Stylosanthinae-Aeschymoneneae-Papilionoideae-Leguminosae) (Rudd, 1981) is one of the central foci of research into the improvement of tropical pastures. These research efforts have been concentrated in Brazil and Australia, and have resulted in a recent series of taxonomic studies dealing with the genus in these two regions of the world (t'Mannetje, 1967, 1977; Ferreira and Sousa Costa, 1977, 1979). All taxonomic treatments of Stylosanthes since that of Vogel in 1838 have accepted his division of the genus into two sections based on the presence or absence of an "axis rudiment" which is considered to be either an aborted secondary axis of the inflorescence (Mohlenbrock, 1958; t'Mannetje, 1967) or the aborted apex of a 1-flowered raceme (Nooteboom, 1961). When consulting the latest studies, it is immediately apparent that there is disagreement in the use of sectional names. The New World studies (Ferreira and Sousa Costa, 1977, 1979) employ sect. Stylosanthes for the species with an "axis rudiment" and sect. Astyposanthes (Herter) Mohlenbrock for the species without the "axis rudiment," while the Old World treatments (t'Mannetje, 1967, 1977; Nooteboom, 1961) use sect. Stylosanthes for the species without an "axis rudiment" and sect. Stylosanthes Vogel for the species with an "axis rudiment." For the uninitiated reader, confusion is often the result from consulting the most recent taxonomic studies, not clarity. The critical specific and subspecific taxa are listed below.
TL;DR: It is shown that adoption of the provision to remove all constraints on the priority of American Code lectotypifications would result in nomenclatural changes in 48 cases as against 10 if the proposal to adopt 1935 as the starting date for priority of lectotypification was adopted.
Abstract: The typification of the 112 Linnaean generic names dating to 1753, for which American Code lectotypifications differ from later ones, is reviewed in the light of two proposals to amend the International Code of Botanical Nomenclature at the XIV International Botanical Congress at Berlin in 1987. As part of the review, Dioscorea sativa L. is lectotypified and thus synonymized under D. villosa, and Agrostis alba L. is placed in synonymy under Poa nemoralis L. The two proposals (Proposals 291 and 297) were both included in the report of the Committee on Lectotypification, and are found to have differential effects in 58 of the 112 cases examined. It is shown that adoption of the provision to remove all constraints on the priority of American Code lectotypifications would result in nomenclatural changes in 48 cases as against 10 if the proposal to adopt 1935 as the starting date for priority of lectotypification was adopted. Moreover, with priority of American Code lectotypifications, changes would arise in the names of subdivisions of families in 4 cases and in names very widely accepted at the generic level in 21 cases, whereas no such changes would occur if a 1935 starting date were adopted. The generic names involved include Agrostis, Andropogon, Apium, Cleome, Cucurbita, Draba, Elymus, Ophrys, Scabiosa, Scirpus and Sisymbrium. At the infrageneric level (including 7 cases in which a few authors recognize segregate genera), changes would be required in 26 cases if Proposal 297 (American Code priority) were adopted on its own, but in only 10 if Proposal 291 (1935 start) were accepted. The authors conclude that stability of nomenclature, at least at the levels of genera and subdivisions of genera of phanerogams, is better served by establishing 1935 as the starting date for priority of lectotypification.
TL;DR: In this paper, a dictionary of animal and plant growth, structure, and behaviour is presented, which contains over 12,000 entries dealing with all aspects of animal growth and behavior.
Abstract: Ecology, statistics, earth sciences, atmospheric sciences, and biochemistry are among the many scientific disciplines that have contributed to the vocabulary of natural history. This dictionary fills the need for a guide to the diverse terminology aimed at the non-specialist. It contains over 12,000 entries dealing with all aspects of animal and plant growth, structure and behaviour.
TL;DR: The interpretation of the phylloclade of Phyllocladus by Keng (1974) as an ancient link between lateral branch systems of progymnosperms and the simple leaves of moder conifers is critically examined in the light of patterns of vascularisation.
Abstract: Summary The interpretation of the phylloclade of Phyllocladus by Keng (1974) as an ancient link between lateral branch systems of progymnosperms and the simple leaves of moder conifers is critically examined in the light of patterns of vascularisation, and his erection of the monogeneric family Phyllocladaceae (Keng, 1973, 1978) is challenged.