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Filtering by: Creator United States Remove constraint Creator: United States Advisor Chambers, Kenton L. Remove constraint Advisor: Chambers, Kenton L. Degree Name Doctor of Philosophy (Ph.D.) Remove constraint Degree Name: Doctor of Philosophy (Ph.D.)

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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:
    States by Harold LeRoy Lint A THESIS submitted to Oregon State University in partial fulfillment 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
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    from 20 he in the United States. An artificial key to the nine species and two varieties of section

  • A taxonomic study in the genus Hackelia in western North America

    Creator:
    Carr, Robert L.
    Abstract:
    A biosystematic study was made on the species of Hackelia of northwest America and adjacent Canada. During the course of the study 140 populations, representing all species and varieties, were transplanted to the greenhouse for study under controlled conditions. Chromosome counts were made for all 14 taxa studied, and intra-...
    Resource Type:
    Dissertation

  • A biosystematic study of some North American species of Agrostis L. and Podagrostis (Griseb.) Scribn. & Merr.

    Creator:
    Carlbom, Curt Gerald, 1932-
    Abstract:
    A taxonomic investigation was made of 24 taxa belonging to the section Trichodium (Michx.) Trin., of Agrostis, and the genus Podagrostis. Experimental methods were employed, including: uniform garden culture of transplants and plants grown from seeds collected in natural populations; breeding studies; physiological and phenological investigations; cytological studies; ecological studies...
    Resource Type:
    Dissertation
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    in the second edition of the Manual of the Grasses of the United States (1950). Lamson

  • A biosystematic study in the genus Aster, section Aster, in western North America

    Creator:
    Dean, Milton Lee
    Abstract:
    A biosystematic investigation was undertaken in 15 species and three subspecies of the genus Aster, in western North America. Previous studies had been based entirely on external morphological features, and it was believed that much could be learned about the natural affinities of the taxa by exploring their cytological and...
    Resource Type:
    Dissertation
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    . Huziwara (35) reported aneuploidy in at least four taxa of the genus in eastern United States. Many

  • Biosystematics of the Mimulus nanus complex in Oregon

    Creator:
    Ezell, Wayland Lee, 1937-
    Abstract:
    A biosystematic study was made in seven populations of Mimulus nanus Hook. & Arn. and M. cusickii (Greene) Piper (Scrophulariaceae) in central Oregon, and a taxonomic revision was made of the four species of section Eunanus reported from Oregon--M. nanus, M. cusickii, M. clivicola Greenm. and M. jepsonii Grant. Mimulus...
    Resource Type:
    Dissertation
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    -desert and montane habitats of the western United States, with four species reported from Oregon

  • Cytotaxonomic studies in the Artemisia ludoviciana polyploid complex of the Pacific Northwest

    Creator:
    Estes, James R.
    Abstract:
    The Artemisia ludoviciana polyploid complex is a highly polymorphic assembledge of eight taxa in the Pacific Northwest, with a chromosome base number of x=9. A cytogenetic analysis of this complex was carried out to determine the sources of its variation, the types of polyploidy present, and the genetic processes active...
    Resource Type:
    Dissertation
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    most widespread in the xerophytic Great Basin and Columbia Plateau of the western United States. Its

  • Systematic and reproductive studies of Mimulus (Scrophulariaceae) in the Pacific Northwest : implications for conservation biology

    Creator:
    Meinke, Robert James
    Abstract:
    The Mimulus washingtonensis complex is a group of morphologically similar species centered in the Pacific Northwest. All are rare, and most are under consideration for listing as endangered. Morphometric and pollination data were used in developing a revised taxonomy for the group. Five species and two varieties are recognized. Mimulus...
    Resource Type:
    Dissertation
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    United States alone, nearly 700 species have been estimated to be critically imperilled (Mlot, 1989

  • The gene-ecology of Crepis nana Richardson and Crepis elegans Hooker in Arctic and Alpine North America

    Creator:
    Legge, Allan Herbert, 1942-
    Abstract:
    A gene-ecological transplant study was made on populations of the Crepis nana and C. elegans complex from the Arctic and Alpine of North America. Transplants were collected from the Brooks Range, Eagle Summit, and Alaska Range in Alaska, the Rocky Mountains in Alberta, the Olympic Mountains in Washington, the Wallowa...
    Resource Type:
    Dissertation
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    State Uni- versity (UTC), United States National Museum (US), Gray Herbarium (G), California Academy

  • 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
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    established throughout the eastern portion of the United States. However, recent studies (Ehrle, 1958