A Biosystematic Study of Some North American Species of Agrostis L. and Podagrostis (Griseb.) Scribn. & Merr PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download A Biosystematic Study of Some North American Species of Agrostis L. and Podagrostis (Griseb.) Scribn. & Merr PDF full book. Access full book title A Biosystematic Study of Some North American Species of Agrostis L. and Podagrostis (Griseb.) Scribn. & Merr by Curt Gerald Carlbom. Download full books in PDF and EPUB format.
Author: Curt Gerald Carlbom Publisher: ISBN: Category : Agrostis Languages : en Pages : 0
Book Description
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 in natural populations. Herbarium exsiccatae including the type material of most of the 24 taxa were studied. In addition, comparative morphological studies were made of several of the taxa in their natural habitats and again in the uniform experimental garden. Twenty-four taxa are recognized in this study. Generic and species descriptions, distributional maps, generic and species keys, photographs of 23 taxa including several types, and photomicrographs of meiotic and mitotic figures of 12 taxa are presented. In addition, the various taxa are discussed individually, and the criteria and concepts used for species delimitation in Agrostis and Podagrostis are presented. Chromosome counts of nine species and two varieties of Agrostis and three species of Podagrostis are reported for the first time. Additional counts of other native taxa confirm earlier published counts. Eleven of the 19 species of Agrostis are hexaploids, four species are known to be tetraploids and two species are octoploids. Two hexaploid groups have been delimited - the A. exarata and A. dieqoensis complexes. The three Podagrostis species, P. aequivalvis, P. humilis and P. thurberiana are diploids, 2n = 14. This chromosome number supports previous morphological evidence that Podagrostis is an independent evolutionary group deserving generic status. Three Old World species of Agrostis, adventive in western North America, have been studied cytologically, and chromosome counts are presented. Agrostis perennans, hitherto unknown in western North America, was collected by the investigator on the Olympic Peninsula of Washington. Putative natural hybridization and introgression were observed between several taxa of Agrostis and Podagrostis, namely: A. diegoensis and A. hallii; A. diegoensis and A. pallens; P. humilis and P. thureriana. Physiological races in P. thurberiana and A. exarata have been studied. Clinal races occur with a north-south distributional pattern in P. thurberiana. Races from southern California flowered under shorter photoperiods, while races from northern California, Oregon and Washington flowered at successively later dates under increased photoperiodic regimes. Mountain ecotypes of A. exarata were obligately long-day plants, while sea-level ecotypes were day-neutral and remontant. Agrostis howellii, a species found near sea level, required a long-day photo-periodic regime and cold vernalization for floral initiation. Autogamy occurs in several of the native species of Agrostis. Facultative autogamy seems to occasion rapid ecotypic and racial diversification with concomitant morphological complexity within the taxa. A tentative phylogenetic scheme is presented. The North American species of Agrostis are believed to comprise two main evolutionary groups; the "primitive" and "derived" species of section Trichodium. The "primitive" taxa are chiefly characterized by: 1) having some species with Old World distributions; 2) more northern and/or widespread distributions; 3) a perennial habit; 4) mostly medium to large anthers; 5) reproducing by allogamy; 6) having tetra-, hexa-, and octoploid chromosome levels; 7) inhabiting mesic and sylvan or bog habitats; 8) occurring on older geological formations and soils. The "derived" species are characterized by: 1) not having any conspecific taxa in the Old World; 2) more southern distributions; 3) being weakly perennial or annual; 4) small anthers; 5) reproducing by autogamy or facultative auto-gamy; 6) having hexa- and octoploid chromosome levels; 7) occupying arid and semi-arid habitats; 8) occurring on newer geological formations and soils
Author: Curt Gerald Carlbom Publisher: ISBN: Category : Agrostis Languages : en Pages : 0
Book Description
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 in natural populations. Herbarium exsiccatae including the type material of most of the 24 taxa were studied. In addition, comparative morphological studies were made of several of the taxa in their natural habitats and again in the uniform experimental garden. Twenty-four taxa are recognized in this study. Generic and species descriptions, distributional maps, generic and species keys, photographs of 23 taxa including several types, and photomicrographs of meiotic and mitotic figures of 12 taxa are presented. In addition, the various taxa are discussed individually, and the criteria and concepts used for species delimitation in Agrostis and Podagrostis are presented. Chromosome counts of nine species and two varieties of Agrostis and three species of Podagrostis are reported for the first time. Additional counts of other native taxa confirm earlier published counts. Eleven of the 19 species of Agrostis are hexaploids, four species are known to be tetraploids and two species are octoploids. Two hexaploid groups have been delimited - the A. exarata and A. dieqoensis complexes. The three Podagrostis species, P. aequivalvis, P. humilis and P. thurberiana are diploids, 2n = 14. This chromosome number supports previous morphological evidence that Podagrostis is an independent evolutionary group deserving generic status. Three Old World species of Agrostis, adventive in western North America, have been studied cytologically, and chromosome counts are presented. Agrostis perennans, hitherto unknown in western North America, was collected by the investigator on the Olympic Peninsula of Washington. Putative natural hybridization and introgression were observed between several taxa of Agrostis and Podagrostis, namely: A. diegoensis and A. hallii; A. diegoensis and A. pallens; P. humilis and P. thureriana. Physiological races in P. thurberiana and A. exarata have been studied. Clinal races occur with a north-south distributional pattern in P. thurberiana. Races from southern California flowered under shorter photoperiods, while races from northern California, Oregon and Washington flowered at successively later dates under increased photoperiodic regimes. Mountain ecotypes of A. exarata were obligately long-day plants, while sea-level ecotypes were day-neutral and remontant. Agrostis howellii, a species found near sea level, required a long-day photo-periodic regime and cold vernalization for floral initiation. Autogamy occurs in several of the native species of Agrostis. Facultative autogamy seems to occasion rapid ecotypic and racial diversification with concomitant morphological complexity within the taxa. A tentative phylogenetic scheme is presented. The North American species of Agrostis are believed to comprise two main evolutionary groups; the "primitive" and "derived" species of section Trichodium. The "primitive" taxa are chiefly characterized by: 1) having some species with Old World distributions; 2) more northern and/or widespread distributions; 3) a perennial habit; 4) mostly medium to large anthers; 5) reproducing by allogamy; 6) having tetra-, hexa-, and octoploid chromosome levels; 7) inhabiting mesic and sylvan or bog habitats; 8) occurring on older geological formations and soils. The "derived" species are characterized by: 1) not having any conspecific taxa in the Old World; 2) more southern distributions; 3) being weakly perennial or annual; 4) small anthers; 5) reproducing by autogamy or facultative auto-gamy; 6) having hexa- and octoploid chromosome levels; 7) occupying arid and semi-arid habitats; 8) occurring on newer geological formations and soils
Author: Curt Gerald Carlbom Publisher: ISBN: Category : Agrostis Languages : en Pages : 446
Book Description
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 in natural populations. Herbarium exsiccatae including the type material of most of the 24 taxa were studied. In addition, comparative morphological studies were made of several of the taxa in their natural habitats and again in the uniform experimental garden. Twenty-four taxa are recognized in this study. Generic and species descriptions, distributional maps, generic and species keys, photographs of 23 taxa including several types, and photomicrographs of meiotic and mitotic figures of 12 taxa are presented. In addition, the various taxa are discussed individually, and the criteria and concepts used for species delimitation in Agrostis and Podagrostis are presented. Chromosome counts of nine species and two varieties of Agrostis and three species of Podagrostis are reported for the first time. Additional counts of other native taxa confirm earlier published counts. Eleven of the 19 species of Agrostis are hexaploids, four species are known to be tetraploids and two species are octoploids. Two hexaploid groups have been delimited - the A. exarata and A. dieqoensis complexes. The three Podagrostis species, P. aequivalvis, P. humilis and P. thurberiana are diploids, 2n = 14. This chromosome number supports previous morphological evidence that Podagrostis is an independent evolutionary group deserving generic status. Three Old World species of Agrostis, adventive in western North America, have been studied cytologically, and chromosome counts are presented. Agrostis perennans, hitherto unknown in western North America, was collected by the investigator on the Olympic Peninsula of Washington. Putative natural hybridization and introgression were observed between several taxa of Agrostis and Podagrostis, namely: A. diegoensis and A. hallii; A. diegoensis and A. pallens; P. humilis and P. thureriana. Physiological races in P. thurberiana and A. exarata have been studied. Clinal races occur with a north-south distributional pattern in P. thurberiana. Races from southern California flowered under shorter photoperiods, while races from northern California, Oregon and Washington flowered at successively later dates under increased photoperiodic regimes. Mountain ecotypes of A. exarata were obligately long-day plants, while sea-level ecotypes were day-neutral and remontant. Agrostis howellii, a species found near sea level, required a long-day photo-periodic regime and cold vernalization for floral initiation. Autogamy occurs in several of the native species of Agrostis. Facultative autogamy seems to occasion rapid ecotypic and racial diversification with concomitant morphological complexity within the taxa. A tentative phylogenetic scheme is presented. The North American species of Agrostis are believed to comprise two main evolutionary groups; the "primitive" and "derived" species of section Trichodium. The "primitive" taxa are chiefly characterized by: 1) having some species with Old World distributions; 2) more northern and/or widespread distributions; 3) a perennial habit; 4) mostly medium to large anthers; 5) reproducing by allogamy; 6) having tetra-, hexa-, and octoploid chromosome levels; 7) inhabiting mesic and sylvan or bog habitats; 8) occurring on older geological formations and soils. The "derived" species are characterized by: 1) not having any conspecific taxa in the Old World; 2) more southern distributions; 3) being weakly perennial or annual; 4) small anthers; 5) reproducing by autogamy or facultative auto-gamy; 6) having hexa- and octoploid chromosome levels; 7) occupying arid and semi-arid habitats; 8) occurring on newer geological formations and soils.
Author: Flora of North America Editorial Committee Publisher: ISBN: 0195310713 Category : Science Languages : en Pages : 941
Book Description
FNA presents for the first time, in one published reference source, information on the names, taxonomic relationships, continent-wide distributions, and morphological characteristics of all plants native and naturalized found in North America north of Mexico.
Author: Flora of North America Editorial Committee, Publisher: OUP USA ISBN: 9780195310719 Category : Science Languages : en Pages : 952
Book Description
Flora of North America brings together for the first time ever in a concise and easy to understand format information on all of the plants growing spontaneously in North America north of Mexico. Volume 24 of Flora North America is one of two volumes on grasses to be published in this series (Volume 25, though it follows sequentially, was published in 2003). Together they will provide a comprehensive, authoritative, illustrated account of this important group of plants. Most of the species treated are either native to North America north of Mexico or are introduced species that are now established in the region, but there are many that do not fit into these categories. Among the additional species are several that the USDA has identified as major weed threats; and others that are known only as cultivated plants, some being cultivated for their ornamental value, others as sources for human food or animal forage. For instance, volume 24 includes such ecologically important genera as Elymus (wheatgrasses), Poa (bluegrasses), and Festuca (fescues), economically important species such as Triticum (wheat), Hordeum (barley), Oryza (rice), and Zizania (wild rice), several ornamental species, including some bamboos, and noxious weeds such as Elymus repens (quackgrass), and Bromus tectorum (cheatgrass). The volume includes identification keys, descriptions, line drawings, and ecological characteristics for each of the species; distribution maps for the native and established species; and a list of commonly encountered synonyms for the accepted names. The treatments, each of which has been extensively reviewed, are based on a combination of original observations and critical review of the literature.
Author: Curt Gerald Carlbom
Author: Curt Gerald Carlbom
Author: Curt Gerald Carlbom
Author: Flora of North America Editorial Committee
Author: Flora of North America Editorial Committee,
Author: 
Author: S. G. Aiken
Author: Canada. Department of Agriculture. Research Branch
Author: 
Author: 
Author: