AN ABSTRACT OF THE THESIS OF Sherry Kay Pittam for the degree of Master of Science in Botany and Plant Pathology presented on 14 March 1995.Title: Pendent Usnea (Lichens; Ascomycetes; Parmeliaceae) in Western Oregon: Taxonomy; Morphological Characters; and Geographic Distribution. Redacted for Privacy Abstract approved. William C. Denison Pendent Usnea species were collected in western Oregon and examined. Character states, such as cortex-medulla-axis ratio; fibril length; papilla diameter; branching patterns; and presence or absence of fibrils, papillae, soredia, isidia; plus chemistry, were recorded and analyzed by inspection for differences.Historical names were researched in the literature. A comparison was made between species concepts used in these accounts, with many conflicting concepts encountered. Selected morphological characters were examined by scanning electron microscope, or dissecting microscope, described, and illustrated. The characters reviewed included articulate fissures; isidia and soredia; cortex-medulla-axis ratio; papillae; and foveate pits.Species determinations were made for field collections. Names were found for all specimens inspected without introducing new names at this time. Eight pendent species were found in western Oregon; they are Usnea cavernosa, Usnea ceratina, Usnea fillpendula, Usnea hesperina subsp. liturata, Usnea inflata, Usnea leucosticta, Usnea longissima, and Usnea merrillii. A practical key to taxa with descriptions is provided and geographic distributions are recorded in tables and maps. Copyright by Sherry K. Pittam 14 March 1995 All Rights Reserved Pendent Usnea (Lichens; Ascomycetes; Parmeliaceae) in Western Oregon: Taxonomy; Morphological Characters; and Geographic Distribution by Sherry K. Pittam A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Master of Science Completed 14 March 1995 Commencement June 1995 Master of Science thesis of Sherry Kay Pittam presented on 14 March 1995 APPROVED: Redacted for Privacy Major Professor, representing Botany and Plant Pathology Redacted for Privacy Chair of Department of Botany and Plant Pat "ology Redacted for Privacy Dean of Gradua hool I understand that my thesis will become part of the permanent collection of Oregon State University libraries. My signature below authorizes release of my thesis to any reader upon request. Redacted for Privacy Sherry Kay Pittam, Author ACKNOWLEDGMENTS I am grateful to my committee members, Dr. William Denison, Dr. Paul Farber, Dr. Bruce McCune, and Dr. Jeff Miller, for assistance and suggestions.I thank Dr. McCune for suggesting this study of the pendent Usnea.I am much indebted to my Major Advisor, Dr. William Denison, for his continuous guidance and support through many years of my education. Dr. John Thomson provided me with several pages of Herre's translation of Motyka which have been of great value.I thank him for his time and effort. Thanks to Bengt Gunnar Jonsson for the translation of a Swedish article, to R. Tabacchi and K. Renhorn for publications, and to the Curators who sent loan material from the following herbaria COLO, DS, 0, PC, SFSU, SRP, WTU, and WWB. DeLorme Mapping of Freeport, Maine kindly gave me permission to print their base maps with overlays of information from this project, using their computer program Map Expert. My thanks to Al Soeldner for his SEM expertise. And finally, to my Mother, who kept me smiling through the final stages; thank you for the encouragement. This study was funded by generous gifts from Dr. William C. Denison; from Northwest Mycological Consultants, Inc., Corvallis, Oregon; and from Betty J. Pittam, Mill City, Oregon. Support for a Graduate Research Assistantship was provided by Dept. of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon; these gifts and support allowed me to complete this study. TABLE OF CONTENTS Page INTRODUCTION 1 A Short Description 1 The Problem 3 The Study Area 4 A Short History 5 METHODS 8 Field Methods 8 Laboratory Methods 9 MORPHOLOGICAL, ANATOMICAL and CHEMICAL CHARACTERS .... 12 Articulate Fissures 12 Branching Patterns 13 Cortex-Medulla-Axis 16 Fibrils, Branch lets, and Spinules 16 Foveate Pits and Wrinkles 18 Internal Coloring 19 Isidia and Soredia, Pseudocyphellae, Papillae, and Tubercles 20 Medulla Density 23 Thallus LengthPendent, Subpendent, and Shrubby 24 Chemical Characters 24 Characters of Doubtful Value 25 Holdfast 25 Color 26 RESULTS and DISCUSSION 27 KEY to the SPECIES 33 TABLE OF CONTENTS (Continued) Page DESCRIPTIONS of the GENUS and SPECIES 36 Usnea Dill. ex Adans. 36 Usnea californica Herre 36 Usnea cavernosa Tuck. 37 Usnea ceratina Ach. 39 Usnea filipendula Stirton 40 Usnea hesperina Mot. subsp. liturata Mot. 42 Usnea inflata Delise 44 Usnea leucosticta Vainio apud Rasanen 46 Usnea longissima (L.) Ach. 47 Usnea merrillii Mat 49 GEOGRAPHIC DISTRIBUTION 51 Primary Habitats and Distribution 51 Distribution of Rare Species 52 FINAL COMMENTS 56 BIBLIOGRAPHY 57 APPENDICES 62 Appendix A Distribution Maps 63 Appendix B Specimen Data 70 Appendix C Other Literature of Interest 82 LIST OF FIGURES Figure Page 1. Longitudinal (250X) and Cross-section (150X) drawings through a typical Usnea thallus branch. 2 2. Diagram of branch cross-section showing CMA measurement points. .. 10 3. Articulate fissures of Usnea hesperina subsp. liturata. 13 4. Branching patterns in Usnea found in this study 14 5. Longitudinal section through an Usnea branch 15 6. Fibril central-axis at contact point with main branch. .17 7. Foveate pits in Usnea hesperina subsp. liturata. 19 8. Isidia with cortex, erupting from the medulla on Usnea inflata 21 9. Papillae with globose top on Usnea ceratina.. 22 10. Tops of eroded papillae on Usnea inflata 23 11. Usnea cavernosa Tuck. 38 12. Usnea ceratina Ach. 39 13. Usnea filipendula Stirt. 41 14. Usnea hesperina Mot. ssp. liturata Mot. 43 15. Usnea inflata Delise 44 16. Usnea leucosticta Vainio. 46 17. Usnea longissima (L.) Ach. 48 18. Usnea merrillii Mot. 49 19. Sites where collections were made during this study. 55 LIST OF TABLES Table Page 1. Measured dimensions and formula for computation of cortex thickness... 11 2. Surface characters exhibited by Usnea taxa considered in this study 28 3. Chemical and structural characters exhibited by Usnea taxa considered in this study. 29 4. Alphabetized list: ratio of axis to total thallus diameter. 30 5. Selected field specimens scored for habitat using the broadest zones of Franklin and Dyrness (1973); other non-classified habitats; and distance to waterbody data. 53 6. Distribution of western Oregon pendent Usnea by county. 54 LIST OF APPENDICES Page APPENDICES 62 Appendix A Distribution Maps 63 Appendix B Specimen Data 70 Appendix C Other Literature of Interest 80 Pendent Usnea (Lichens; Ascomycetes; Parmeliaceae) in Western Oregon: Taxonomy; Morphological Characters; and Geographic Distribution INTRODUCTION A Short Description Lichens are organisms that result from a symbiosis of algae and fungus, a relationship that, in lichens, is generally considered of some benefit to both partners. These two organisms combine together forming a unique body type called a thallus. The fungus consists of minutely tiny thread-like material called hyphae. In the lichen thallus, the algae generally remain as single cells. The alga is sometimes referred to as the phycobiont and the fungus is referred to as the mycobiont (Hale, 1983).The fungal hyphae in the medullary layer wrap around and contact individual alga cells. Photosynthesis products are produced by the algae and transferred to the fungus. Pendent species ofUsneain western Oregon are characterized by a hanging thallus (Fig. 1), often exceeding 30 cm long, occasionally as short as 10 cm; this thallus is usually composed of a system of multiple branches, resembling hanging tangles of pale green string. The green alga phycobionts inUsneaare generally most numerous on the outer edge of the medulla, near the outer cortical layer.This cortical layer is formed from tightly compressed fungal hyphae, and is variously thickened and translucent. The algae in allUsneataxa are species ofTrebouxia; there are no cyanobacteria (blue-green algae) reported for species ofUsnea. The individual branches of theUsneathallus are rounded to angular in cross- section, with a central-axis of tightly compacted conglutinated fungal hyphae surrounded by a second layer of fungal hyphae, the medulla, which is loosely to tightly interwoven.The central axis is strong and elastic.Its presence is an 2 important field character separating Usnea from other fruticose lichens.This outer cortical layer, covers the inner two layers, and is present in varying degrees, broken Fig. 1:Longitudinal (250X) and Cross-section (150X) drawings through a typical Usnea thallus branch. Whole thallus branches approximately actual size. by disintegration, erosion of papillae, or by formation of pores, tubercles, or soralia (described later in this paper), and at times is almost totally eroded and lacking. The color varies from light straw yellow-green to dark olive-green, to reddish hues, often changing, fading or browning during storage.For additional details of the lichen symbiosis, and specific thallus structural details refer to Hale (1983), or Lawrey (1984). 3 The Problem Species in the genusUsneaare a major component of woodlands in western Oregon. As an epiphyte on trees or shrubs, they occur in many habitats in this area. Yet, they are very poorly known.The taxonomy, nomenclature,