Atlas of the flora of New England: Dicots - Paeoniaceae to Ericaceae: Introduction

ABSTRACT. Dot maps are provided to depict the distribution at the county level of the taxa of Magnoliophyta: Paeoniaceae to Ericaceae (corresponding to Flora of North America, Volume 8 (Flora of North America Editorial Committee 2009)) growing outside of cultivation in the six New England states of the northeastern United States. The maps treat the 147 taxa (species, subspecies, varieties, and hybrids, but not forms) 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, atlas, distribution, Crassulaceae, Ericaceae, Grossulariaceae, Myrsinaceae, Primulaceae, Saxifragaceae.

This article is the seventh in a series (Angelo and Boufford, 1996, 1998, 2000, 2007, 2010, 2011) 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 it will be updated as new information becomes available.

This project encompasses all vascular plants (lycophytes, 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 seventh installment includes the families in Magnoliophyta: Paeoniaceae to Ericaceae corresponding to the families treated in Flora of North America, Vol. 8 (Flora of North America Editorial Committee 2009). Of the 147 taxa treated, 45 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 specimen 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). These can also be found at http://neatlas.org/Intro-Pterid&Gym.html.

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. The Angiosperm Phylogeny Website (Stevens 2001 onwards) should be consulted for a continuously updated treatment of families and their inclusive 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 Flora of North America, Vol. 8 (Flora of North America Editorial Committee 2009) and from Missouri Botanical Garden's Index to Plant Chromosome Numbers [website http://http://www.tropicos.org/NameSearch.aspx?projectid=9; St. Louis, MO]

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 (which includes excluded taxa) will aid readers in finding familiar names that have been transferred to other taxa:

Empetraceae => Ericaceae

Monotropaceae => Ericaceae

Primulaceae (in part) => Myrsinaceae

Primulaceae (in part) => Theophrastaceae

Pyrolaceae => Ericaceae

Saxifragaceae (in part) => Grossulariaceae

Saxifragaceae (in part) => Penthoraceae

Arctostaphylos (in part) => Arctous

Cassandra => Chamaedaphne

Cassiope (in part) => Harrimanella

Chiogenes => Gaultheria

Glaux (in part) => Lysimachia

Ledum (in part) => Rhododendron

Leucothoë (in part) => Eubotrys

Loiseleuria => Kalmia

Naumbergia (in part) => Lysimachia

Oxycoccus (in part) => Vaccinium

Pyrola (in part) => Orthilia

Saxifraga (in part) => Micranthes

Sedum (in part) => Hylotelephium

Sedum (in part) => Phedimus

Sedum (in part) => Rhodiola

Tillaea => Crassula

The following species have been reported from our area but are excluded for the reasons noted:

Agarista populifolia (Lamarck) Judd [no specimen located; reported from Rhode Island]

Anagallis minima (Linnaeus) E. H. L. Krause (Centunculus pumilis (Swarz) Kuntze) [collected in Worcester Co., Massachusetts; no specimens yet accessioned in herbaria that are the basis for this atlas]

Lysimachia quadriflora Sims [no specimen located; reported from Massachusetts with vouchers at MIN, but vouchers not located there]

Pieris floribunda (Pursh) Bentham & Hooker f. [no voucher for wild occurrence found; reported from Vermont]

Primula wilsonii Dunn var. anisodora (Balfour f. & Forrest) A. J. Richards (P. anisodora Balfour f. & Forrest) [no specimen located; reported from Berkshire Co., Massachusetts; apparently now identified as Primula japonica A. Gray]

Rhododendron columbianum (Piper) Harmaja [a single 1871 specimen from Mt. Washington, New Hampshire recently annotated as this species, and far from its known range, is excluded until its status in New England is better understood.]

Rhododendron tomentosum Harmaja [a single 1947 specimen from a bog in Carroll Co., New Hampshire recently annotated as this species, and distant from its known range, is excluded until its status in New England is better understood.]

Rhododendron vaseyi A. Gray [no voucher for wild occurrence found; reported from Massachusetts]

Saxifraga hyperborea R. Brown [no specimen located; reported from Mount Washington, New Hampshire]

Styrax japonicus Siebold & Zuccarini [no specimen located; reported from Connecticut (Flora of North America Editorial Committee 2009)]

ACKNOWLEDGMENTS. We thank the curators and directors of the herbaria of the New England Botanical Club, the Harvard University Herbaria, 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 facilitating access to the herbarium and to the notebooks of Harry E. Ahles at the University of Massachusetts (Amherst) and for kindly answering requests for information after our visit. James Hinds also generously checked information on voucher specimens at the University of Maine (Orono). The following persons also checked certain records for us at their respective institutions: Janet Sullivan, Walter Judd, and Anita F. Cholewa. In particular we thank the following individuals for repeated checking of specimens at their institution: Robert Capers of the University of Connecticut and Lisa I. Palmer of Dartmouth College.