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Filtering by: Creator United States. Forest Service. Intermountain Region Remove constraint Creator: United States. Forest Service. Intermountain Region Advisor Chambers, Kenton L. Remove constraint Advisor: Chambers, Kenton L. Non-Academic Affiliation Oregon State University. Graduate School Remove constraint Non-Academic Affiliation: Oregon State University. Graduate School

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  • A revision of Juncus subgenus genuini (Juncaceae) in the Pacific states

    Creator:
    Lint, Harold LeRoy
    Abstract:
    A study was made of the subgenus Genuini of the genus Juncus in the Pacific States, California, Oregon and Washington. Extensive morphological comparisons, geographical distributions, habitat differences and observations of apparent presence or absence of natural hybrids provided the major data sources. Cytological studies were made, but were inconclusive. Eleven...
    Resource Type:
    Dissertation
    Full Text:
    taxa in the Pacific region of the United States that have long been a source of confusion to

  • Autecology, reproductive ecology, and demography of Astragalus australis var. olympicus (Fabaceae)

    Creator:
    Kaye, Thomas N.
    Abstract:
    The goal of this study was to gather information on the autecology, reproductive ecology, and population dynamics of Astragalus australis var. olympicus as a baseline for conservation strategies and to help explain its restricted range. Approximately four thousand individuals occurred in four known population centers in the Olympic Mountains, Olympic...
    Resource Type:
    Masters Thesis
    Full Text:
    Oregon State University in partial fulfillment of the requirements for the degree of Master of Science

  • The ecology and reproduction of Sophora leachiana Peck (Fabaceae)

    Creator:
    Crowder, Cheryl Alison
    Abstract:
    The goal of the study was to collect data on the ecology and reproduction of Sophora leachiana in order to help explain the rarity and restricted range of this species. There are 13 known populations of S. leachiana, occurring in a 29 by 6.4 km area in the Siskiyou Mountains...
    Resource Type:
    Masters Thesis
    Full Text:
    States Forest Service and herbarium specimens at Oregon State University (OSC) and the University of

  • Taxonomy of Phacelia section Miltitzia (hydrophyllaceae)

    Creator:
    Halse, Richard R.
    Abstract:
    A systematic study was made of the species comprising Phacelia section Miltitzia. These species, which are commonly found in the Great Basin physiographic province of western North America, are distinguished from other members of Phacelia by their yellow, marcescent corollas and their transversely corrugated seeds. This project utilized morphological, cytological,...
    Resource Type:
    Dissertation
    Full Text:
    from 20 he in the United States. An artificial key to the nine species and two varieties of section

  • Phenotypic variation in diploid and tetraploid populations of Claytonia perfoliata (s.l.) (Portulacaceae)

    Creator:
    Miller, John M.
    Abstract:
    Meiotic chromosome counts from 200 populations of Claytonia (Montia) perfoliata (sensu lato) reveal a polyploid pillar complex based on three morphologically different, chemically distinct, and geographically defined diploids. The basic chromosome number is x=6. Diploid C. perfoliata Willdenow with linear juvenile leaves and deltoid mature basal leaves ranges southeastward from...
    Resource Type:
    Dissertation
    Full Text:
    and the western United States to southern Mexico. Young inflorescences were fixed in the field using

  • Origin and distribution of polyploid Achillea (Compositae) in western North America

    Creator:
    Tyrl, Ronald J.
    Abstract:
    A cytogeographical study was made of populations of tetraploid (n=18) and hexaploid (n=27) Achillea millefolium (Compositae- Anthemideae) from the Pacific Coast states. There is a complex distributional pattern, involving overlapping ranges, mixed populations, migration of one form into areas occuplied by the other, pentaploid hybrids, and septaploid and octoploid plants....
    Resource Type:
    Dissertation
    Full Text:
    established throughout the eastern portion of the United States. However, recent studies (Ehrle, 1958

  • Ecology and reproduction in Collomia macrocalyx Brand (Polemoniaceae)

    Creator:
    Joyal, Elaine
    Abstract:
    Populations of Collom ia macrocalyx Brand were located and observed in order to determine the distribution, ecology, and reproductive biology of this species and probable relationships to other members of the genus. The purpose of the study was to obtain information that would explain the restricted range of the species...
    Resource Type:
    Masters Thesis
    Full Text:
    . They are best developed in the western United States, and all but two genera are native to this

  • Taxonomy and ecology of Mentzelia mollis Peck and related species

    Creator:
    Glad, Judith B.
    Abstract:
    A study was made to clarify the relationships of Mentzelia mollis Peck and two poorly understood taxa of Mentzelia (Loasaceae) to the other members of the genus, its sections, and its subsections, and to describe the general ecology of each taxon. Within the genus, the section Trachyphytum is characterized by...
    Resource Type:
    Masters Thesis
    Full Text:
    . Paleobotanical Considerations The floristic history of the Intermountain Region shows it to have been

  • A systematic and ecological study of Astragalus diaphanus (Fabaceae)

    Creator:
    Wright, Carolyn E.
    Abstract:
    Astragalus diaphanus is a rare plant endemic to the John Day River drainage of north-central Oregon. This species has several interesting features, including the dimorphism of its fruit and its geographical isolation from the two nearest taxonomically related species, which occur in Colorado. This study addressed the species' distribution and...
    Resource Type:
    Masters Thesis
    Full Text:
    Academy of Sciences (CAS & DS); Intermountain Herbarium, Utah State University (UTC); New York Botanical

  • Biosystematic studies of Phacelia capitata (Hydrophyllaceae), a species endemic to serpentine soils in southwestern Oregon

    Creator:
    Shelly, J. Stephen
    Abstract:
    Phacelia capitata Rruckeberg is a member of the Phacelia magellanica polyploid complex (species group Magellanicae), a group of wide-ranging, polymorphic perennials in western North America related to the South American P. secunda (= P. magellanica). The purpose of this project was to determine, to the extent possible, the interrelationships of...
    Resource Type:
    Masters Thesis
    Full Text:
    United States (Cronquist, 1981). Of the 18 genera recognized by Constance (1963), 16 are primarily