Atlas of the flora of New England: Dicots - Magnolidae & Hamamelidae: Introduction

ABSTRACT. Dot maps are provided to depict the distribution at the county level of the taxa of Magnoliidae & Hamamelidae growing outside of cultivation in the six New England states of the northeastern United States. Of the 228 taxa (species, subspecies, varieties, and hybrids, but not forms) treated, all are mapped based primarily on specimens in major herbaria of Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, and Connecticut, with most data derived from the holdings of the New England Botanical Club Herbarium (NEBC). Brief synonymy to account for names used in standard manuals and floras for the area, habitat and chromosome information, and common names are also provided.

Key Words: flora, New England, flora, New England, atlas, distribution, Magnoliidae, Hamamelidae.

This article is the fifth in a series that will present the distributions of the vascular flora of New England in the form of dot distribution maps at the county level (see Key Map). The atlas is posted on the Internet at http://neatlas.org/ where we will attempt to keep it updated.

This project encompasses all vascular plants (pteridophytes and spermatophytes) at the rank of species, subspecies, and variety growing independent of cultivation in the six New England states. Hybrids are also included, but forms and other ranks below the level of variety are not. The dots are based on voucher specimens primarily in New England herbaria (of colleges, universities, botanical gardens, and public museums) representing reproducing populations outside of cultivated habitats. This fifth installment includes the families in subclasses Magnoliidae and Hamamelidae. For convenience, these are the families treated in Volume 3 of the Flora of North America (Flora of North America Editorial Committee 1997). Of the 228 taxa treated, 79 are not native to the region. Future accounts will treat the distribution of additional non-monocot angiosperms.

The habitat data are distillations from a variety of sources augmented by our own field observations. An attempt was made to indicate habitat information as it applies to a particular taxon in New England rather than to the entire range of the taxon. Such information is omitted where habitat is not indicated on the label and where we also lack personal knowledge of the plant in New England. All omissions of habitat information are for a few introduced taxa and for all hybrids.

We plan to gather this series of articles, together with additional background material, into a separate volume upon completion of all the installments. It is our hope, in the meantime, that these articles will stimulate additional field work to supplement the distributions portrayed in the maps. The New England Botanical Club herbarium has proven to be the most important resource for this project. We are eager to receive information on voucher specimens in public herbaria documenting range extensions and filling county gaps in distributions. Similarly, because the atlas of the New England flora will be continuously updated as new information becomes available, we are eager to receive notification of published corrections of cytological information and new, documented chromosome counts for taxa in the New England flora.

Materials and methods are as outlined in Angelo and Boufford (1996) and are not repeated here.

TAXONOMY AND FORMAT

The taxonomy and nomenclature adopted for this work essentially follow that of the Flora of North America project in progress, except that families, genera, and species are arranged alphabetically. The families and their circumscription do not necessarily reflect current views on relationships or composition. Contrary to the Flora of North America treatment, the traditional inclusion of Fumariaceae in Papaveraceae is retained since this is supported by the most recent evidence (Wang, W., et. al., 2009). The Angiosperm Phylogeny Website (Stevens, P. F., 2001 onwards) should be consulted for a continuously updated treatment of families and their included genera. Named and unnamed hybrid taxa are placed alphabetically at the end of the genus in which they occur. Unnamed hybrids combine the names of the progenitors alphabetically by epithet. Taxa that are not native to New England are indicated by uppercase text. Unpublished names are not used, even if publication is pending.

Chromosome numbers are taken from Volume 3 (Magnoliidae & Hamamelidae) of the Flora of North America series (Flora of North America Editorial Committee 1997) and from Missouri Botanical Garden's Index to Plant Chromosome Numbers at http://mobot.mobot.org/W3T/Search/ipcn.html.

Synonymy is provided primarily with respect to names accepted in standard manuals covering New England published from 1950 onward, including Fernald (1950), Gleason (1952), Gleason and Cronquist (1991), and Seymour (1982). Synonyms have not been provided where the distribution for the synonymized name does not include New England.

The following list will aid readers in finding familiar names that have been transferred to other taxa:

Anemone (in part) => Pulsatilla

Anemonella => Thalictrum

Corydalis (in part) => Capnoides

Dicentra (in part) => Lamprocapnos

Hepatica => Anemone

The following species are reported from our area, but no voucher specimens were located, or the substantiating specimens were misidentified, or the voucher specimen is in question as to identity or occurrence in the wild:

Carya laciniosa (F. Michaux) Loudon [voucher specimens collected in Massachusetts and Maine are deemed not established in the wild]

Celtis tenuifolia Nuttall [no specimen seen; reported from Connecticut]

Clematis florida Thunberg var. florida C.K. Schneider [no specimen seen; reported from Connecticut]

Clematis vitalba Linnaeus [no specimen located; reported from Maine in Flora of North America Editorial Committee (1997)]

Consolida regalis Gray [no specimen seen; reported from Connecticut]

Delphinium grandiflorum Linnaeus [voucher specimen collected in Vermont is deemed not established in the wild]

Fatoua villosa (Thunberg) Nakai [voucher specimen collected in Connecticut is deemed not established in the wild]

Juglans X quadrangulata (Carrière) Rehder [no specimen seen; reported from Massachusetts]

Nelumbo nucifera Gaertner [no specimen located; reported from Massachusetts in Flora of North America Editorial Committee (1997)]

Papaver argemone Linnaeus [no specimen seen; reported from Connecticut]

Parietaria floridana [specimen in NEBC from NH misidentified]

Parietaria hespera B.D. Hinton [label of the NEBC voucher specimen from New Hampshire is the result of a mixed label; P. hespera is native to the deserts of the southwestern U.S. and northwestern Mexico.]

Platanus X acerifolia (Aiton) Willdenow [voucher specimen collected in Massachusetts is deemed not established in the wild]

Quercus phellos Linnaeus [no specimen seen; reported from Connecticut]

Quercus X sargentii Rehder [no specimen seen; reported from Massachusetts]

Ranunculus laxicaulis Darby [no specimen seen; reported from Connecticut, apparently based upon application of this name to specimens of R. ambigens S. Watson]

Urtica chamaedryoides Pursh [no specimen seen; reported from Massachusetts]

ACKNOWLEDGMENTS. We thank the curators and directors of the herbaria of the New England Botanical Club, Harvard University, the University of Massachusetts, the University of Vermont, and the University of Connecticut for allowing access to their collections. For the University of Maine herbarium we used their exceptional online database of Maine specimens (http://herbaria.umaine.edu/). We are grateful also to Karen Searcy for allowing access to the notebooks of Harry E. Ahles at the University of Massachusetts (Amherst), for bringing to our attention some new voucher specimens there and for checking information and the identity of a voucher specimen. We thank Donald Les and Robert Capers for checking information on specimens at the University of Connecticut (Storrs). Janet Sullivan kindly checked certain herbarium vouchers at the University of New Hampshire (Durham). Christopher Campbell and James Hinds also generously checked information on voucher specimens at the University of Maine (Orono). Magnus Lidén kindly provided information on Capnoides. Walter Kittredge checked on the location of a specimen at the Harvard University Herbaria. Craig Layne checked information on a herbarium specimen at Dartmouth College for which we are thankful. We appreciate Elizabeth Allen checking information on two specimens in the herbarium at the University of Vermont.Lastly, we thank the two reviewers (one being Arthur Haines) of this paper for helpful comments and suggestions.