Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 13 of 13

Full-Text Articles in Life Sciences

The Euphorbiaceae Of Sonora, Mexico, Victor W. Steinmann, Richard S. Felger Jan 1997

The Euphorbiaceae Of Sonora, Mexico, Victor W. Steinmann, Richard S. Felger

Aliso: A Journal of Systematic and Floristic Botany

This publication is an account of the Euphorbiaceae in the state of Sonora, México. Nineteen genera, 143 species, and three additional varieties are recorded for the state; three species expected within the state are also treated. One species of Acalypha and three species and one subspecies of Euphorbia are described. Dichotomous keys for the identification of genera and species are provided. Bibliographic citations, type information, synonyms, brief habit descriptions, times of reproduction, habitat preferences as well as elevational range within Sonora, geographical distribution, and representative specimens are given for each species. When appropriate, notes on uses, taxonomic or nomenclatural problems, …


Two New Species Of Uncinia (Cyperaceae) From Chile, Gerald A. Wheeler Jan 1997

Two New Species Of Uncinia (Cyperaceae) From Chile, Gerald A. Wheeler

Aliso: A Journal of Systematic and Floristic Botany

Two new species of Uncinia (Cyperaceae) are described from Chile. Both are local endemics, with U. chilensis known from VIII (Bío Bío) and IX (Araucanía) regións of central Chile and U. araucana from IX Región only.


Wood Anatomy Of Buddlejaceae, Sherwin Carlquist Jan 1997

Wood Anatomy Of Buddlejaceae, Sherwin Carlquist

Aliso: A Journal of Systematic and Floristic Botany

Quantitative and qualitative data are presented for 23 species of Buddleja and one species each of Emorya, Nuxia, and Peltanthera. Although crystal distribution is likely a systematic feature of some species of Buddleja, other wood features relate closely to ecology. Features correlated with xeromorphy in Buddleja include strongly marked growth rings (terminating with vascular tracheids), narrower mean vessel diameter, shorter vessel elements, greater vessel density, and helical thickenings in vessels. Old World species of Buddleja cannot be differentiated from New World species on the basis of wood features. Emorya wood is like that of xeromorphic species …


Additions To The Vascular Flora Of San Clemente Island, Los Angeles County, California, With Notes On Clarifications And Deletions, Timothy S. Ross, Steve Boyd, Steve Junak Jan 1997

Additions To The Vascular Flora Of San Clemente Island, Los Angeles County, California, With Notes On Clarifications And Deletions, Timothy S. Ross, Steve Boyd, Steve Junak

Aliso: A Journal of Systematic and Floristic Botany

The number of vascular plant taxa reported from San Clemente Island, California, is briefly summarized. Recent additions to the vascular flora are presented and, with one exception, representative voucher specimens are cited as substantiation. Of the taxa di scussed, 68 are previously unreported taxa, and six are substantiations of previously dubious reports. An additional dozen taxa are cited in relation to clarifications or deletions. Based on current knowledge, we estimate the known flora to consist of 396 species with an additional 19 infraspecific taxa represented. Of these 415 taxa, 69.2% (272 speciesl15 additional subspecies or varieties) are considered indigenous to …


Phylogeny Of Polemoniaceae Based On Nuclear Ribosomal Internal Transcribed Spacer Dna Sequences, J. Mark Porter Jan 1997

Phylogeny Of Polemoniaceae Based On Nuclear Ribosomal Internal Transcribed Spacer Dna Sequences, J. Mark Porter

Aliso: A Journal of Systematic and Floristic Botany

Nuclear ribosomal internal transcribed spacer (ITS) DNA sequences are used to estimate the phylogeny of 53 members of Polemoniaceae, representing all but two genera of the family. Fitch parsimony analysis of equal-weighted nucleotide sites result in 1080 minimal-length trees. However, when alignment-ambiguous positions are removed and an II: 10 transition to transversion weighting is imposed only eight trees are found. These data are used to address two issues: I) patterns of diversification in Polemoniaceae, and 2) the circumscription and monophyly of the genus Gilia. Although the monophyly of Polemoniaceae is well supported, relationships inferred among the earliest diverging lineages …


Hierarchial Roots And Shoots Or Opera Jehovae Magna! (Psalms 111:2), Dan H. Nicolson Jan 1997

Hierarchial Roots And Shoots Or Opera Jehovae Magna! (Psalms 111:2), Dan H. Nicolson

Aliso: A Journal of Systematic and Floristic Botany

The philosophy of Linnaeus's classification, Systema Naturae, is briefly reviewed, as well as those of post-Linnaean systems of plant classification. Texts of current codes of nomenclature pertaining to hierarchy, including associated rank terminations, are compared.


Exploring Alternative Systems Of Classification, Kathleen A. Kron Jan 1997

Exploring Alternative Systems Of Classification, Kathleen A. Kron

Aliso: A Journal of Systematic and Floristic Botany

Classification involves the development of a system of naming clades that can represent evolutionary relationships accurately and concisely. Using the acid-loving heath plants (Ericales) as an example, one can explore the application of different classification methods. The Linnean system of naming retains the traditional hierarchical framework (named ranks) and allows for the application of many cuqently used names. The "phylogenetic systematic" approach recommends the removal of an absolute hierarchy but allows retention of traditionally used endings such as -aceae. Historical usage of these names can lead to confusion when the names are used within a discussion or text, especially when …


Problems In Cladistic Classification: Higher-Level Relationships In Land Plants, Peter R. Crane, Paul Kenrick Jan 1997

Problems In Cladistic Classification: Higher-Level Relationships In Land Plants, Peter R. Crane, Paul Kenrick

Aliso: A Journal of Systematic and Floristic Botany

Recent cladistic analyses of green plants recognize an extensive hierarchical series of relatively well-supported monophyletic groups. Translating this hierarchical pattern of relationships into a usable and informative written classification is important for purposes of scientific communication, research and teaching. However, in the context of the "Linnean" hierarchy, as manifested in the current International code of Botanical Nomenclature (ICBN), effecting this translation confronts substantial practical difficulties--especially the proliferation of hierarchical levels. These problems are exacerbated by the current emphasis of the ICBN on a hierarchy in which different ranks have different formal rank-based endings. These difficulties could be ameliorated by de-emphasizing …


Classification: More Than Just Branching Patterns Of Evolution, Tod F. Stuessy Jan 1997

Classification: More Than Just Branching Patterns Of Evolution, Tod F. Stuessy

Aliso: A Journal of Systematic and Floristic Botany

The past 35 years in biological systematics have been a time of remarkable philosophical and methodological developments. For nearly a century after Darwin's Origin of Species, systematists worked to understand the diversity of nature based on evolutionary relationships. Numerous concepts were presented and elaborated upon, such as homology, parallelism, divergence, primitiveness and advancedness, cladogenesis and anagenesis. Classifications were based solidly on phylogenetic concepts; they were avowedly monophyletic. Phenetics emphasized the immense challenges represented by phylogeny reconstruction and advised against basing classifications upon it. Pheneticists forced reevaluation of all previous classificatory efforts, and objectivity and repeatability in both grouping and …


The Linnaean Hierarchy And The Evolutionization Of Taxonomy, With Emphasis On The Problem Of Nomenclature, Kevin De Queiroz Jan 1997

The Linnaean Hierarchy And The Evolutionization Of Taxonomy, With Emphasis On The Problem Of Nomenclature, Kevin De Queiroz

Aliso: A Journal of Systematic and Floristic Botany

During the post-Darwinian history of taxonomy, the Linnaean hierarchy has maintained its role as a means for representing hierarchical taxonomic relationships. During the same period, the principle of descent has taken on an increasingly important role as the basis for reformulated versions of fundamental taxonomic concepts and principles. Early in this history, the principle of descent provided an explanation for the existence of taxa and implied a nested, hierarchical structure for taxonomic relationships. Although an evolutionary explanation for taxa contradicted the Aristotelian context within which the Linnaean hierarchy was developed, the nested, hierarchical structure of taxonomic rela· tionships implied by …


Karyotypes And Idiograms Of Some Western North American Species Of Lotus (Fabaceae), William F. Grant Jan 1997

Karyotypes And Idiograms Of Some Western North American Species Of Lotus (Fabaceae), William F. Grant

Aliso: A Journal of Systematic and Floristic Botany

Karyotypes and idiograms are presented for 12 species (L. argophyllus var. argophyllus, L. crassifolius, L. dendroideus var. dendroideus, L. grandifiorus, L. humistratus, L. oblongifolius var. oblongifolius, L. stipularis, L. scoparius var. scoparius, L. salsuginosus var. salsuginosus, L. rigidus, L. wrangelianus, L. wrightii) and 3 varieties (L. argophyllus var. argenteus, L. nevadensis var. douglasii, L. scoparius var. brevialatus) of Lotus L. (Fabaceae) belonging to four different groups of the genus (Hosackia, Syrmatium, Microlotus, and Simpteria). The chromosome number for L. dendroideus var. dendroideus (2n = 14) is reported …


Vegetative Proliferation In Polypogon Monspeliensis (Gramineae), Eric H. Roalson, Kelly W. Allred Jan 1997

Vegetative Proliferation In Polypogon Monspeliensis (Gramineae), Eric H. Roalson, Kelly W. Allred

Aliso: A Journal of Systematic and Floristic Botany

No abstract provided.


Uncinia (Cyperaceae) Of Ecuador, Gerald A. Wheeler, Paul Goetghebeur Jan 1997

Uncinia (Cyperaceae) Of Ecuador, Gerald A. Wheeler, Paul Goetghebeur

Aliso: A Journal of Systematic and Floristic Botany

Nine species of Uncinia (Cyperaceae: Caricoideae) are recorded from Ecuador, one of which, U. ecuadorensis, is newly described and illustrated here. Descriptions, illustrations, distribution maps, and both artificial and vegetative keys are provided for the nine species, and for some uncinias additional taxonomic, phytogeographic and ecological comments are made. A lectotype is designated for the name U. lenuis.