This thesis is a study of the native and naturalized species of Salix in Utah, and is based upon the following methods. A review of all available literature was accomplished in order to compile a list of species. Type specimens were obtained from the University of California at Berkeley, the Smithsonian Institution, and the Gray Herbarium of Harvard University, University of Utah, and Utah State University. About five-hundred specimens were collected in twenty counties during the fall fo 1965 and the spring of 1966. The identification of the willows in this study was based upon type specimens, annotations by Carleton R. Ball, and descriptions and keys in the literature. As a result of this study twenty-one species are known to occur in the state. Three separate keys have been compiled for the identification of species based upon vegetative characteristics, pistillate flowers, and staminate flowers. Descriptions of the species were made from the specimens that were available for study. Species distribution maps were compiled and one representative herbarium specimen is cited for each county. Habitat information obtained from herbarium labels and field observations is included. The work has been illustrated by including photographs of specimens.

The cryptogamic flora of several soil crusts of arid regions in southern Utah was determined. Twenty-two lichens, Six mosses and fifty-four algal species were identified and their relative abundance estimated.

A considerable amount of study material has beccme available since the revision of the genus in 1900 by Shear, and the revision of the section Bromopsis in 1952 by Wagnon. A number of cytological studies have been done in recent years; and Wagnon's work pointed out the need for a comprehensive study of the entire genus. This study is a taxonomic revision of the Genus Bromus for the State of Utah, and contains illustrations and descriptions of the species; synonomy; distribution maps; and discussions of many of the important aspects of the economics, ecology, and historical treatment. I have recognized 17 species and 2 varieties as being present in the State, and these, along with another 4 closely allied or formerly cited species or varieties reported for Utah, are separated by means of a comprehensive dichotomous key based on the natural grouping of these grasses into sections within the genus. Much of the research has been based on herbarium study of the morphological variation for the separation of taxa, and was supplemented with extensive field observation and collection during the past decade.

Atmospheric deposition (AD) is a significant source of nutrient loading to waterbodies around the world. However, the sources and loading rates are poorly understood for major waterbodies and even less understood for local waterbodies. Utah Lake is a eutrophic lake located in central Utah, USA, and has high nutrient levels. Recent research has identified AD as significant sources for nutrient loading to the lake to better understand the dust AD sources, we sampled suspected source locations and collected deposition samples around the lake. We analyzed these samples using Inductively Coupled Plasma (ICP) for 25 metals to characterize their elemental fingerprints. We then compared the lake samples to the source samples to determine likely source locations. We computed spectral angle, coefficient of determination, multi-dimensional scaling, and radar-plots to characterize the similarity of the samples. We found that lake deposition samples were more similar to local sources than to distant sources. This suggests that the major source of atmospheric deposition onto Utah Lake is the local empty fields south and west of the lake and not the farther playa sources as previously suggested. Preliminary data suggest that dust AD is associated with dry, windy conditions and is episodic in nature. We show that AD from dust deposition is likely a small portion of the overall AD nutrient loading on Utah Lake, with the dry and precipitation source contributing the majority of the load.

The purpose of this thesis has been to make a collection of the seeds of herbaceous dicotyledonous garden flowers of Utah, to examine their external structural characteristics and to prepare keys for their classification. A collection of the seeds of 146 species of garden flowers has been made, and includes species of 41 families. The seeds have been cleaned and dried and a collection stored in labelled vials and left in the Botany Department of the Brigham Young University. Keys have been prepared for the identification of the families, genera, and species. As far as possible external characteristics--such as color, size, and texture--which can be seen without the use of magnification, have been used. For seeds which are too small or which have characteristics too similar to be distinguished with the naked eye, a millimeter scale and a binocular microscope have been used. The term "seed" has been used to designate any propagules. Descriptions of the families and species have been included with the keys. Drawings have been made of the seeds of each species reported. In preparing the drawings a "Camara Lucida" was attached to a binocular microscope and the outlines of the seeds carefully followed. Details of structure and texture were drawn by hand with the aid of a binocular microscope. The seeds were drawn to scale and the measurements included with the drawings. The photographed copies of the drawings were reduced to one-half the size of the originals. Although there has been no attempt to make this work all-inclusive, most of the herbaceous dicotyledonous garden flowers found in Utah have been reported. It is hoped that the study will be of value to those interested in seed identification and that it may serve as a step toward further work in this field.

Cercocarpus ledifolius communities of Utah were sampled to determine which measured environmental characters were influential in determining community structure and dynamics. Nineteen, one-tenth acre stands were sampled by 25 equally spaced .25m2 quadrats. Plant frequency, cover, density, height, diameter, age, elevation, slope and exposure were determined for curl-leaf mahogany within the study area. Soil depth and soil samples were analyzed for texture, pH and soluble salts. Curl-leaf mahogany is found almost entirely on arid rocky slopes, canyon ledges, and plateaus at relatively high elevations on all exposures. The soils were invariably shallow and slightly acidic with sandy loam soils being most common. Soluble salts were low in all the soils analyzed. Over 90 percent of the prevalent species were perennial in habit. Reproduction of curl-leaf mahogany was considered poor. Elevation, soluble salts, soil pH, exposure and percent silt in the soil together accounted for 74 percent of the variation observed in the site quality index computed for curl-leaf mahogany in the communities sampled.

This study is an attempt to consolidate the information already known about the trees of Utah and to extend our knowledge of these trees. An intensive study was made of the available literature. The tree specimens of the herbaria of the Utah State University, University of Utah, Brigham Young University and the Regional Office of the Forest Service at Ogden were examined. These studies were supplemented with extensive field work in various parts of the state. From this information, keys and descriptions of the genera and species were written and distribution maps for each tree and illustrations of many of the trees made.

This present paper is an attempt to open the field of bryology in the state of Utah. It is necessarily a limited treatment both from the standpointof the number of species and the area. It represents the efforts of one summer's collection and the preparation of the manuscript and illustrations. The collection was taken at Mount Timpanogosby the students of the Alpine Summer School of the Brigham Young University during the 1925 session.

A taxonomic investigation of the algal flora of the Brigham Young University campus was conducted from October 1971 to August 1972. This algal flora consisted of 27 genera and 36 species of Chlorophyta, 2 genera and 2 species of Euglenophyta, 32 genera and 106 species of Bacillariophyceae (including 16 genera and 33 species of soil diatoms), 1 genus and 2 species of Chrysophyta excluding diatoms and 6 genera and 14 species of Cyanophyta. Diatoms were the predominent algae in this study. Chlorococcum humicola, Vaucheria geminata, Amphora normani, Hantzschia amphioxys and Oscillatoria sancta were prominent in the greenhouses. In the arboretum pond, Melosira varians, Synedra ulna var. subaegualis and Cymbella cistula were abundant in the winter whereas Spirogyra dubia, Spirogyra jugalis and Spirogyra porticalis grew throughout the year, especially in the late spring. Diatoma tenue var. elongatum, Diatoma vulgare, Cocconeis pediculus and Gomphonema parvulum were prominent stream algae in the early summer. Cladophora glomerata grew in large nmbers at stream site two in the winter.

The study of the East Tintic Mountains was undertaken because no extensive research concerning the plant species present has ever been done. The East Tintic Mountains are in central Utah in Juab, Utah and Tooele Counties. They are about fifty five air miles south-southwest of Salt Lake City. The range is approximately forty two miles long and from one and one-half miles to twelve miles wide. An attempt was made to collect representatives of all vascular plants found on the mountain range. This work presents two hundred and eleven species, representing fifty two families.