Styrax in Cultivation: Evaluation of an Underrepresented Ornamental Genus by Matthew S. Lobdell A thesis submitted to the Faculty of the University of Delaware in partial fulfillment of the requirements for the degree of Masters of Science in Plant & Soil Sciences Summer Semester 2013 © 2013 Matthew S. Lobdell All Rights Reserved Styrax in Cultivation: Evaluation of an Underrepresented Ornamental Genus by Matthew S. Lobdell Approved: __________________________________________________________ John J. Frett, Ph.D. Professor in charge of thesis on behalf of the Advisory Committee Approved: __________________________________________________________ Blake C. Meyers, Ph.D. Chair of the Department of Plant & Soil Sciences Approved: __________________________________________________________ Mark W. Rieger, Ph.D. Dean of the College of Agriculture & Natural Resources Approved: __________________________________________________________ James G. Richards, Ph.D. Vice Provost for Graduate and Professional Education ACKNOWLEDGMENTS Due to the wide variety of topics covered in this project, I was fortunate to be able to call on the aid and assistance of many. I’d like to first thank my committee members, Dr. John Frett, Dr. Tom Pizzolato, and Dr. Tomasz Aniśko for their guidance throughout all phases and aspects of the project. I’d also like to thank the late Dr. J.C. Raulston for his interest in the group, who was arguably the most important player in terms of raising awareness of Styrax from merely an odd, predominantly Asian relative of the Halesia, to a far more diverse group, now gaining recognition in both gardens and the nursery trade. Next, I’d like to thank Dr. Peter Fritsch of the California Academy of Sciences both for providing me with several references to aid in my understanding of the genus, many from his recent work with the systematics of Styrax, making the cultivated component of the group much easier to understand. In the multiple site visits made during this project, Mark Weathington of the JC Raulston Arboretum, Dr. Michael Dosmann, Kyle Port, & Kathryn Richardson of the Arnold Arboretum, and Tom Clark of the Polly Hill Arboretum were all very helpful in granting me access to and showing me around their collections. Several personnel associated with public gardens or the nursery trade were also of great help for their swift and detailed responses to my email queries: Dr. Koen Camelbeke of Arboretum Wespalaar (Belgium), Michael Wenzell of the Atlanta Botanical Garden, Dr. Wolfgang Bopp of the Sir Harold Hillier Gardens (United Kingdom), Richie Steffan of the Elisabeth C. Miller Botanical Garden, Dr. Sandra Reed of the United States National Arboretum, Jamie Shiffer and Barbara Whitcraft of iii Hershey Gardens, Brian Upchurch of Highland Creek Nursery, Joe Dahl of the Regional Parks Botanical Garden, and Dr. Dennis Werner of North Carolina State University. Finally, I’d like to thank Dr. Art Tucker of Delaware State University for providing me with references and reagents for use during chromosome counting methods, as well as Dr. Tom Ranney of North Carolina State University for sharing information in regards to the flow cytometry of the group. iv TABLE OF CONTENTS LIST OF TABLES .................................................................................................... ix LIST OF FIGURES .................................................................................................. xii ABSTRACT............................................................................................................. xx 1 GENUS DESCRIPTION ................................................................................ 1 Introduction .................................................................................................... 1 Taxonomic History of Styracaceae ............................................................ 1 Unique Characteristics of Styrax ............................................................... 4 Distribution .................................................................................................... 5 Morphology .................................................................................................... 6 Habit ......................................................................................................... 6 Leaves ...................................................................................................... 6 Stems ........................................................................................................ 7 Flowers ..................................................................................................... 7 Fruit .......................................................................................................... 8 Anatomy ......................................................................................................... 8 Petiole Vasculature ................................................................................... 8 Wood ........................................................................................................ 9 Chromosome Numbers............................................................................ 10 Nomenclature and Taxonomic History .......................................................... 12 Early Treatments and Synonymous Genera ............................................. 12 Series and Sections ................................................................................. 14 Gender .................................................................................................... 15 Etymology .............................................................................................. 16 Conservation Concerns ................................................................................. 16 2 STYRAX IN CULTIVATION ........................................................................ 21 History in Cultivation ................................................................................... 21 v Resin....................................................................................................... 21 Composition and Uses ....................................................................... 21 Exudation Procedure ......................................................................... 23 Ornamental ............................................................................................. 24 Introduction....................................................................................... 24 Ornamental Characteristics and Value ............................................... 24 Propagation ....................................................................................... 26 Materials & Methods .................................................................................... 26 Results .......................................................................................................... 29 Descriptions of Cultivated Species ................................................................ 33 Styrax section Styrax P.W.Fritsch............................................................ 33 Styrax series Cyrta P.W.Fritsch ......................................................... 34 Styrax agrestis (Loureiro) G.Don................................................. 34 Styrax americanus Lamarck ........................................................ 36 Styrax calvescens Perkins ............................................................ 40 Styrax confusus Hemsley ............................................................. 43 Styrax dasyanthus Perkins ........................................................... 47 Styrax faberi Perkins ................................................................... 49 Styrax formosanus Matsumura..................................................... 51 Styrax glabrescens Bentham ........................................................ 53 Styrax grandifolius Aiton ............................................................ 56 Styrax hemsleyanus Diels ............................................................ 59 Styrax hookeri C.B.Clarke ........................................................... 61 Styrax japonicus Siebold & Zuccarini .......................................... 63 Styrax limprichtii Lingelsheim & Borza ...................................... 74 Styrax macrocarpus Cheng .......................................................... 75 Styrax obassia Siebold & Zuccarini ............................................. 76 Styrax odoratissimus Champion ex Bentham ............................... 80 Styrax serrulatus Roxburgh ......................................................... 81 Styrax shiraianus Makino ............................................................ 83 Styrax supaii Chun & F. Chun ..................................................... 85 Styrax rugosus Kurz .................................................................... 86 Styrax tonkinensis (Pierre) Craib ex Hartwich .............................. 87 Styrax wilsonii Rehder ................................................................. 89 Styrax wuyuanensis S.M.Hwang .................................................. 91 Styrax series Styrax P.W.Fritsch ........................................................ 92 v i Styrax officinalis Linnaeus........................................................... 92 Styrax platanifolius Engelmann ex Torrey ................................... 95 Styrax redivivus (Torrey) L.C. Wheeler ......................................101