AN ABSTRACT OF THE THESIS OF Harold LeRoy Lint for the degree cf Doctor of Philosophy in the Botany Department pre cñ on April 15, 1977 Title: A REVISION OF jUNCUS SUBGENUS CENUINI (JUNCACEAE) IN THE PACIFIC STATES Abstract approved: Redacted for Privacy Dr. Kenton L. Chambers A study was made of the subgenus Genuini of the genus Juncus in the Pacific States, California, Oregonand Washington. Extensive morphological comparisons, geographi- cal distributions, habitat differences andobservations of apparent presence or absence ofnatural hybrids provided the major data sources. Cytological studies were made, but were inconclusive. Eleven species and nine subspecies are recog- nized, comprising four species complexes. The Juncus effusus complex includes three broadly sympatric speciesand five subspecies, J. effusus subsp. pacificus,subsp pugetensi and subsp. austrocalifornicus; J.exiguus subs!). exiguus and subsp. gracins; and J. hesperius. The J. balticus complex including J. breweri, J. lescurii, J.textilis and four subspecies of J. halticus, forms anextensive syngameon of intergrading populations. The widely distriudzed J.LAlticus subsp. mexicanus apparently hybridizes naturally with each of the other species and subspecies in the complex,except the coastal J. balticus subsp. occidentalis which hybridizes with J. breweri. Juncus balticus subsp. cascadensis and subsp. vallicola are mostly montane and interior taxa, the latter reaching the coast in the San Francisco Bay and Puget Sound regions. Juncus lescurii of the San Francisco Bay region is considered to be a probable hybrid between the coastal dune species, J. breweri, and one or more subspecies of J. balticus. A third complex, J. filiformis and J. patens appears to be distinctive and presents no taxonomic problems. Juncus drummondii and J. parryi, which comprise a fourth complex, are usually considered to be part of subgenus Genuini, although they differ from the other species in several important characters. No comprehensive observations were made of these two distinctive species, their inclusion in this study being limited to taxonomic considerations. A Revision of Juncus subgenus Genuini (Juncaceae) in the Pacific States by Harold LeRoy Lint A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Completed April 15, 1977 Commencement June 1977 APPROVED: Redacted for Privacy_ Professor of Botany Redacted for Privacy Chairman of the Departmentof Botany and Plant Pathology Redacted for Privacy Dean of Graduate School Date thesis is presented April 15, 1977 ACKNOWLEDGEMENTS I wish to gratefully acknowledge the effortsof many people, named and unnamed, who have assistedme in this pro- ject throughout the years. I am especially indebted tomy major professor, Dr. Kenton L. Chambers, withoutwhose guidance, encouragement, hospitality, andspecial efforts on my behalf, this study would not have been completed. I am also grateful to my graduate committee fortheir patience and understanding. Among my fellow graduate students, the contri- butions of several were outstanding. Dr. Curt Carlbom and Mr. Dennis Jacques helped to maintainmy greenhouse collection at Corvallis in my absence. Dr. Carlbom and Dr. Allan Legge were especially helpful in assisting me with cytological techniques. Many friends and students, whowere aware of my interest in Juncus, broughtme specimens from areas that I had not visited. Special thanks in this regard are given to Dr. Carlbom, Dr. Milton Dean, Dr. Knut Faegri, and Dr.Jerome Dimitman. The latter collected specimens forme from central Mexico, enabling me to compare those plants with Pacific States taxa. Dr. Elizabeth McClintock and Dr. Carlyn Halde were very helpful in locating and driving me to collection sites in San Francisco, and Mr. and Mrs. Richard Bakken helped in a similarway in the vicinity of Bass Lake, California. I am grateful to the directorsor curators of the herbaria who loaned the specimensso essential to this study. Among these, Dr. Lawrence Heckard, Dr.Elizabeth McClintock, and Dr. Robert Thorne put forth specialefforts in my behalf. Helpful suggestions and informationwere obtained through correspondence with other students of Juncus. These included Dr. Frederick Hermann, Dr. L. A. S.Johnson, Dr. Seymour H. Sohmer, and Dr.C. A. Stace. This study was financed in part by theaward of a National Science Foundation ScienceFaculty Fellowship. Final illustrations andmaps were prepared with the assist- ance of Kornelius Evenhuis and Robert Marvos. Finally, but by no means least, has beenthe help of my wife, Mary Eleanor, who assisted me in making collections and in organizing and typing the finaldraft of this thesis. Without her patience, understanding, andhelp, this study would not have been possible. TABLE OF CONTENTS I. Introduction 1 II. Taxonomic History 3 III. Materials and Methods 11 IV. Results 16 Taxonomic Concepts 16 Geographical Relationships and Variability . 21 Hybridization 34 Longevity of Plants 35 Seed Germination 38 Chromosome Counts 38 Taxonomic Utility of Morphological Characteristics 43 V. Taxonomy 59 Key to the Pacific States Taxa 60 Nomenclature and Description of Taxa 67 Additional Taxonomic Notes 182 VI. Literature Cited 184 LIST OF ILLUSTRATIONS ANDMAPS Figure Page 1 Diagram of possible relationshipsamong some species and subspecies of theJuncus balticus complex 19 2 Diagram of possible relationshipsbetween some spe- cies and subspecies of theJuncus effusus complex 20 3 Distribution of hybrids betweensubspecies of Juncus balticus in the Pacific States 23 4 Sympatric distribution of Juncushesperius and sub- species of Juncus effusus andJuncus exiguus in California and Josephine andJackson Counties, Oregon 27 5 Sympatric distribution of Juncushesperius, the sub- species of Juncus effusus andJuncus exiguus subsp. gracilis in Oregon north ofJosephine County and in Washington 28 6 A. Inflorescence of Juncus exiguussubsp. gracilis with parts labeled B. Basal bract types 52 7 Portions of culms and theupper cataphyll apices of Pacific States taxa of the Juncuseffusus complex showing some of the morphologicalcharacters useful in distinguishing between them 71 8 Pacific States distribution of thesubspecies of Juncus effusus and hybrids 73 9 Distribution of Pacific States subspeciesof Juncus exiguus and their hybrids 87 10 Pacific States distribution ofJuncus hesperius 97 11 Juncus balticus subsp. vallicola, baseof plant and subsp. cascadensis, inflorescence andbase of plant 106 12 Pacific States distribution ofJuncus balticus subsp. cascadensis and subsp. vallicola 108 Figure Page 13 Juncus balticus subsp. mexicanus,habit, rhizome, and single culm and blade 116 14 Pacific States distribution ofJuncus balticus subsp. mexicanus showing usual absenceof leaf blades in the northern portion ofits distribution 118 15 Pacific States distribution of Juncusbalticus subsp. occidentalis and hybrids between subsp.occidentalis and Juncus breweri 130 16 Habit and inflorescence of Juncus breweri 140 17 Pacific States distribution of Juncusbreweri, Juncus lescurii and Juncus textilis withsome of their hybrids 142 18 Distribution of Juncus breweri and Juncuslescurii in the San Francisco Bay region 144 19 Juncus lescurii and Juncus balticus subsp. occidentalis 151 20 Inflorescence and base of Juncus textilis 159 21 Pacific States distribution of Juncuspatens and Juncus filiformis 165 22 Pacific States distribution of Juncusparryi and Juncus drummondii 176 LIST OF TABLES Table Page I Mixed Populations of Taxa of the Juncus effusus Complex with the Percent of Each Taxonper Sample Plot 25 II Percentages of Rhizomes Remaining Alive After Different Periods of Time 36 III Relative Ability of Taxa of Juncus subgenus Genuini to Survive Under Prolonged Refrigera- tion 37 IV Summary of Seed Germination Data Showing Earliest and Maximum Percent Germination and Oldest Viable Seeds of Pacific States Juncus subgenus Genuini 39 V Approximate Chromosome Numbers of some Species and Subspecies of Juncus subgenus Genuini 42 VI Plant Heights of Juncus subgenus Genuini in the Pacific States 45 VII Culm Diameters of Juncus subgenus Genuini in the Pacific States 47 VIII Spathe Lengths of Juncus subgenus Genuini in the Pacific States 49 IX Upper Cataphyll Lengths of Juncus subgenus Genuini in the Pacific States 50 XInflorescence Lengths of Juncus subgenus Genuini in the Pacific States 54 XI Percent Distribution of Basal Bract Types in the Pacific States Juncus effusus complex 55 XII Outer Tepal Length of Juncus subgenus Genuini in the Pacific States 57 A REVISION OF JUNCUSSUBGENUS GENUINI(JUNCACEAE) IN THE PACIFIC STATES I. INTRODUCTION The cosmopolitan subgenusGenuini Buchenau of the includes a number of genus JuncusLinnaeus, family Juncaceae, that have taxa in the Pacificregion of the United States long been a source ofconfusion to taxonomists. This is especially true of Juncuseffusus Linnaeus and Juncus balticus Willdenow, theirvarieties, and speciesallied to them (Engelmann 1866, 1868;Watson 1880; Buchenau1890, 1906; Coville 1893; Piper 1906;Fernald and Wiegand 1910;Parish Munz 1959; 1910; Jepson 1922, 1923;Abrams 1940; Mason 1957; Peck 1961; Hitchcock 1969). This revision of Juncussubgenus Genuini of the Pacific States is an attempt toclarify the taxonomic status possible of the subgenus in thisregion, and to suggest some relationships between theincluded taxa as a basisfor fur- morphological compari- ther study. The primary approach is a in the field and son ofpopulations through observations