Life Sciences Commons^™

Wood And Stem Anatomy Of Menispermaceae, Sherwin Carlquist

Aliso: A Journal of Systematic and Floristic Botany

Qualitative and quantitative data are presented for 17 collections of 15 species representing 14 genera. One species is a shrub (Cocculus laurifolius), one a subshrub (C. trilobus), and the remainder are lianas. Successive cambia are analyzed with respect to ontogeny and histology of products. Whether any Menispermaceae may or may not plesiomorphically lack successive cambia would require a more extensive survey of the family. Apomorphic absence of successive cambia is likely for species with subshrub growth forms (Cocculus trilobus, Menispermum canadense L.). Lianoid Menispermaceae share the following features: successive cambia, wide vessels, wide rays, …

Patterns Of Dilatation Growth In Ficus Pumila And Ficus Sycomorus, Simcha Lev-Yadun

Aliso: A Journal of Systematic and Floristic Botany

Dilatation growth occurs in the secondary phloem rays, in the axial secondary phloem parenchyma, and in the parenchyma of the cortex of Ficus pumila (a Iiana) and Ficus sycomorus (a tree). Dilatation growth in Ficus pumila is mostly the result of meristematic activity, but in Ficus sycomorus it is the result of both meristematic activity and increase in cell size. Dilatation meristem is formed in the rays in various patterns: in the center of the ray, at one or two of the ray's margins, in horizontal or diagonal strips (relative to the axis) in the ray, or in more than …

Studies In Macrosiphonia (Apocynaceae): Generic Recognition Of Telosiphonia, James Henrickson

Aliso: A Journal of Systematic and Floristic Botany

Woodson recognized two subgenera within Macrosiphonia (Apocynaceae: Apocynoideae), a South American subgenus Eumacrosiphonia, and a North American subgenus Telosiphonia each with five species. Both taxa are characterized by low subshrub-shrub, nonviny growth habits, white, long-tubed, vespertine corollas of a type associated with moth pollination. Their distinctive anther and style-tip characteristics show each is related to a group of genera around Mandevilla and Mesechites. The two subgenera, however, differ strongly from each other in inflorescence, style-head structure, and pollen size indicating that they are not sister taxa and that Macrosiphonia as currently recognized is polyphyletic. Thus the subgenus Telosiphonia …

Baccharis Malibuensis (Asteraceae): A New Species From The Santa Monica Mountains, California, R. Mitchell Beauchamp, James Henrickson

Aliso: A Journal of Systematic and Floristic Botany

Baccharis malibuensis is described from the Malibu Lake region of the Santa Monica Mountains, Los Angeles County, California. It is closely related to Baccharis plummerae subsp. plummerae but differs in having narrow, subentire, typically conduplicate, sparsely villous to mostly glabrous leaves with glands occurring in depressions on the adaxial surface, more cylindrical inflorescences, and a distribution in open chaparral vegetation. The new taxon shares some characteristics with B. plummerae subsp. glabrata of northwestern San Luis Obispo County, e.g., smaller leaves, reduced vestiture, and occurrence in scrub habitat, but the two taxa appear to have developed independently from B. p. subsp. …

Population Structuring And Patterns Of Morphological Variation In Californian Styrax (Styracaceae), Peter Fritsch

Aliso: A Journal of Systematic and Floristic Botany

Recent studies of genetic variation within and among populations and phylogenetic estimates have provided evidence bearing on the evolutionary history and taxonomy of Styrax in California (S. redivivus). In this paper, data from these studies are further analyzed and integrated with new data from morphology to gain insight into the nature and taxonomic significance of character variation within this species. Six morphological characters thought to be important in the delimitation of infraspecific taxa within S. redivivus were measured on 52 herbarium specimens and analyzed with Pearson correlations and multivariate methods. Five characters are significantly associated with latitude and …

A Revision Of The Euphorbia Dioscoreoides Complex (Euphorbiaceae), Victor W. Steinmann

Aliso: A Journal of Systematic and Floristic Botany

No abstract provided.

Using Confocal Microscopy In The Study Of Plant Structure And Development, Mark P. Running, Elliot M. Meyerowitz

Aliso: A Journal of Systematic and Floristic Botany

The widespread application of confocal laser scanning microscopy has revolutionized biological imaging. We have developed a protocol for using confocal microscopy to examine the development of wild type and mutant Arabidopsis thaliana, overcoming the technical difficulties associated with examining whole-mounted plant tissue. This allowed us to rapidly determine the underlying cellular defects that lead to the morphological changes visible in several mutants, and has led to a greater understanding of the mechanisms involved in the control of floral organ number.

Genetic Dissection Of The Morphological Evolution Of Maize, John Doebley

Aliso: A Journal of Systematic and Floristic Botany

Maize (Zea mays ssp. mays) and its wild progenitor, teosinte (Z. mays ssp. parviglumis) differ dramatically in inflorescence and plant architecture despite the fact that their evolutionary divergence occurred within the past 10,000 years or less. To elucidate the genetic control of the morphological differences between maize and teosinte, my colleague and I employed quantitative trait locus mapping with molecular markers. Results indicated that most of the variation in plant and inflorescence morphology between maize and teosinte can be explained by five restricted regions of the genome. In this paper, characterization of three of these regions …

Crossroads, Milestones, Amd Landmarks In Insect Development And Evolution: Implications For Systematics, Rob Desalle, Donat Agosti, Michael Whiting, Beatriz Perez-Sweeney, James Remsen, Rick Baker, James Bonacum, Ranhy Bang

Aliso: A Journal of Systematic and Floristic Botany

Our understanding of insect development and evolution has increased greatly due to recent advances in the comparative developmental approach. Modem developmental biology techniques such as in situ hybridization and molecular analysis of developmentally important genes and gene families have greatly facilitated these advances. The role of the comparative developmental approach in insect systematics is explored in this paper and we suggest two important applications of the approach to insect systematics--character dissection and morphologicallandmarking. Exi~ng morphological characters can be dissected into their genetic and molecular components in some cases and this will lead to more and richer character information in systematic …

Bouteloua Chihuahuana (Gramineae), A New Nomenclatural Combination, J. Travis Columbus

Aliso: A Journal of Systematic and Floristic Botany

A revision of the Euphorbia dioscoreoides complex (subgenus Agaloma) is provided. Euphorbia dioscoreoides ssp. attenuata and E. eglandulosa, both from Mexico, are proposed as new; E. digitata is reduced to synonymy under E. subpeltata. Representative specimens are cited, and distributional and ecological data are provided.

Diversity And Evolution Of Seedling Baupläne In Perlargonium (Geraniaceae), Cynthia S. Jones, Robert A. Price

Aliso: A Journal of Systematic and Floristic Botany

The genus Pelargonium (Geraniaceae) exhibits tremendous variation in growth form. We apply a broadly defined concept of Bauplan in our study of growth form, architectural and anatomical features of early seedling development in the type subgenus. We analyze variation in these features within a phylogenetic framework based on sequence comparisons of internal transcribed spacer regions (ITS) of nuclear ribosomal DNA.

Preliminary ITS sequence comparisons show strong support for two major clades. One major clade contains two subgroups, one consisting of three previously recognized sections of more or less woody shrubs and subshrubs (sections Pelargonium, Glaucophyllum and Campylia), and …

Does The Monocot Mode Of Leaf Development Characterize All Monocots?, Geeta Bharathan

Aliso: A Journal of Systematic and Floristic Botany

Patterns of early leaf development in monocots are analyzed in a phylogenetic context. Recent developmental and phylogenetic studies enable this reevaluation of the leaf base model of the developing monocot leaf. Two questions are addressed: a) is the presence of the Vorläuferspitze (fore-runner tip) invariably correlated with development of the lamina from the lower leaf zone? and b) was the ancestral monocot characterized by the leaf base mode of development? Scanning electron microscopic observations are made of young primorida using the mold and cast method. These data are combined with data from the literature and examined in a phylogenetic context …

Integrating Cellular And Molecular Approchaes Into Studies Of Development And Evolution: The Issue Of Morphological Homology, Andrés Collazo, Scott E. Fraser

Aliso: A Journal of Systematic and Floristic Botany

Understanding the development and evolution of complex morphological characters requires broad, multidisciplinary approaches. By combining biological imaging, phylogenetic analyses, embryological manipulations and additional modem molecular techniques (e.g., whole mount in situ hybridization), we can address fundamental questions, such as the determination of homology. Many of the novel structures that evolved in vertebrates and distinguish them from their ancestors (such as jaws and the mechanosensory lateral line) are derived embryonically from two migratory ectodermal tissues, neural crest and/or various epidermal placodes. In particular, time-lapse cinematography of fluorescently labeled cells in living Xenopus and fish embryos has proved a powerful technique, revealing …

Introduction To The Symposium: "The New Morphology: Potential For Integrating New Techniques And Concepts", Elizabeth Zimmer

Aliso: A Journal of Systematic and Floristic Botany

No abstract provided.