Field Guide to Carex of New England Lisa A. Standley A Special Publication of the New England Botanical Club About the Author: Lisa A. Standley is an environmental consultant. She obtained a B.S, and M.S. from Cornell University and Ph.D. from the University of Washington. She has published several articles on the systematics of Carex, particularly Section Phacocystis, and was the author of several section treatments in the Flora of North America. Cover Illustrations: Pictured are Carex pensylvanica and Carex intumescens. Field Guide to Carex of New England Lisa A. Standley Special Publication of the New England Botanical Club Copyright © 2011 Lisa A. Standley Acknowledgements This book is dedicated to Robert Reed, who first urged me to write a user-friendly guide to Carex; to the memory of Melinda F. Denton, my mentor and inspiration; and to Tony Reznicek, for always sharing his expertise. I would like to thank all of the people who helped with this book in so many ways, particularly Karen Searcy and Robert Bertin for their careful editing; Paul Somers, Bruce Sorrie, Alice Schori, Pam Weatherbee, and others who helped search for sedges; Arthur Gilman, Melissa Dow Cullina, and Patricia Swain, who carefully read early drafts of the book; and to Emily Wood, Karen Searcy, and Ray Angelo, who provided access to the herbaria at Harvard University, the University of Massachusetts, and the New England Botanical Club. CONTENTS Introduction .......................................................................................................................1 Guide to the Groups ..........................................................................................................8 Groups and Species Treatments Group 1 ...............................................................................................................11 Group 2 ...............................................................................................................18 Group 3 ...............................................................................................................34 Group 4 ...............................................................................................................40 Group 5 ...............................................................................................................49 Group 6 ...............................................................................................................55 Group 7 ...............................................................................................................64 Group 8 ...............................................................................................................70 Group 9 ...............................................................................................................76 Group 10 .............................................................................................................83 Group 11 .............................................................................................................87 Group 12 .............................................................................................................90 Group 13 .............................................................................................................98 Group 14 ...........................................................................................................104 Group 15 ...........................................................................................................112 Group 16 ...........................................................................................................122 Group 17 ...........................................................................................................125 Group 18 ...........................................................................................................132 Group 19 ...........................................................................................................146 Group 20 ...........................................................................................................153 Group 21 ...........................................................................................................157 Glossary ........................................................................................................................166 Taxonomic Relationships..............................................................................................169 Index ...........................................................................................................................180 Introduction INTRODUCTION I wrote this book to share my enthusiasm for the beauty and complexity of the genus Carex, and to help other botanists appreciate and identify its species. I began this enterprise at the urging of my friend Bob Reed, who wanted an illustrated guide that amateurs could easily use. The book provides easy-to-use keys, descriptions and illustrations of the 188 species of Carex in New England, and is intended to allow botanists to identify species in the field without recourse to microscopic characters or difficult technical keys. Carex is a member of the Cyperaceae, the sedges, a world-wide family of wind-pollinated, grass-leaved monocots. The sedges are probably most closely related to the rushes (Juncaceae): both families share unique characters of pollen development, chemistry, and chromosome structure. Carex is one of the largest genera of the Cyperaceae, with approximately 2000 recognized species, and is predominantly a northern hemisphere group, although species occur in some southern hemisphere temperate and mountain regions. Carex has a unique flowering structure of unisexual (separate male and female) flowers with the female flowers enclosed in a bottle-like structure called a perigynium. Its closest relatives are the small northern genus Kobresia and the southern hemisphere genus Uncinia, both of which have perigynium-like structures. Species of Carex occur in all New England habitats, from coastal sand dunes and salt marshes to the highest alpine summits, and are generally good habitat indicators since species tend to have fairly narrow ecological ranges and high habitat specificity. While carices tend to be dominants in most New England wetland communities, only 42 percent of our species occur in wetlands. Many of these are common and widely distributed, although some are highly specialized and infrequent. More species occur in upland habitats (forests, meadows, and open disturbed sites) than in wetlands, but the upland species are rarely community dominants and may be very patchy in their distribution. Most of the Carex species in New England are native to our region, with only eight adventive species: six introduced from Europe or Asia (Carex caryophyllea, C. hirta, C. kobomugi, C. ovalis, C. panicea, and C. spicata) and two from the midwest (C. oklahomensis and C. praegracilis). Most of these introductions persist in small scattered populations and have not become weedy, except for Carex praegracilis, a salt- tolerant species that has become established along highways. In 2004, a total of 96 species (51 percent of the total Carex flora of New England) were listed on the state Endangered Species lists, as endangered, threatened, special concern, or historic. With the exception of a few globally rare species, the majority of New England species of conservation interest are more common in other parts of their range and are associated with specialized habitats in New England – alpine summits, calcareous wetlands, Atlantic white cedar swamps, rich deciduous woods, or prairie remnants. “Flora Conservanda1”, the New England Plant Conservation Program’s list of New England plants in need of conservation, lists 53 species of Carex that are of regional conservation concern. Seven species are globally rare (C. garberi, C. lupuliformis, C. mitchelliana, C. oronensis, C. polymorpha, C. schweinitzii, and C. wiegandii). None of these, however, are on the Federal Endangered Species list. The regionally rare species include taxa with a wide range of geographic affinities – northern boreal species that reach their southern limits in northern Maine or on the high peaks of the White Mountains, southern coastal plain species that reach their northern limits in Rhode Island or southern Massachusetts, and north-central prairie and rich deciduous woods species that reach their eastern limits in New England. Six species were listed by Flora Conservanda as historic in New England – C. atherodes, C. nigromarginata, C. praticola, C. rariflora, C. willdenowii, and C. woodii. Two of these (C. atherodes and C. willdenowii) have recently been rediscovered. This book includes all of the potentially historic species except C. woodii, which was likely never actually found in New England. 1 Brumback, W.E and L.J. Mehrhoff. 1996. Flora Conservanda: New England. The New England Plant Conservation Program (NEPCoP) list of plants in need of conservation. Rhodora 98:235-361. 1 Introduction All of the New England species of Carex are herbaceous perennials with underground perennial stems (rhizomes) that may grow mostly vertically (producing clusters of shoots) or horizontally (producing single shoots). These above-ground shoots are annual and bear the leaves and flowers. The growth of these perennial rhizomes is termed “vegetative reproduction” and it is how plants persist in one place for years or decades. The great diversity within the genus is related