Atlas of the flora of New England: Poaceae: Introduction

ABSTRACT. Dot maps are provided to depict the distribution at the county level of the Poaceae growing outside of cultivation in the six New England states of the northeastern United States. The 342 taxa (species, subspecies, varieties and hybrids, but not forms) are mapped based on specimens in the major herbaria of Maine, New Hampshire, Vermont, Massachusetts, Rhode Island and Connecticut, with primary emphasis on the holdings of the New England Botanical Club herbarium (NEBC). Brief synonymy to account for names used in recent manuals and floras for the area, habitat, chromosome information, and common names are also provided.

Key words: flora, New England, atlas, distribution, Poaceae

This article is the second 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. The atlas is being posted on the internet at http://neatlas.huh.harvard.edu/ where we will attempt to keep it updated

This work encompasses all vascular plants (pteridophytes and spermatophytes) at the rank of species, subspecies and variety growing outside of cultivation in the six New England states. Hybrids are also be included, but forms and other ranks below the level of variety are not. The dots are based primarily on voucher specimens in the herbaria of New England representing reproducing populations, or plants persisting long after cultivation when it is uncertain that they are actually naturalized. This second installment comprises the Poaceae. The number of taxa treated is 345 of which 342 are mapped, 154, a remarkably high 45 percent, are not native to New England, and 6 are hybrids. Future accounts will treat the distribution of the rest of the angiosperms.

We intend to gather this series of articles, together with additional background material, into a separate volume upon completion of all the maps., 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, which has proven to be the most important resource for this project, is especially eager to receive specimens documenting range extensions. We also would like to be informed of such specimens in other herbaria. 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.

The taxonomy and nomenclature adopted for this work essentially follow that of a revision of A. Hitchcock and A. Chase's Manual of the Grasses of the United States (Barkworth et al., editors), except that genera are arranged alphabetically, as are species within genera. Named and unnamed hybrid taxa are placed alphabetically at the end of the genus. Unnamed hybrids combine the names of the progenitors alphabetically by epithet. Taxa that are not native to New England are indicated by uppercase text. A number of pending name changes (primarily in Panicum) could not be implemented since they were still unpublished at the time this work was sent to press.

Cited chromosome numbers are taken from indices prepared by Cave (1958a, 1958b. 1959a, 1959b, 1960, 1961, 1962, 1963, 1964, 1965), Goldblatt (1981, 1984, 1985, 1988, ), Goldblatt and Johnson (1990, 1991, 1994, 1996), Löve & Löve (1975), Moore (1973, 1974, 1977) and Ornduff (1967, 1968, 1969). Very few of the counts are based on material from New England, but instead reflect counts made from throughout the range of the taxon.

Synonymy is provided primarily with respect to names used in standard manuals covering New England published from 1950 onward, including Fernald (1950), Gleason (1952), Gleason and Cronquist (1991), Seymour (1982), and Hitchcock and Chase (1951).

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

Agropyron (in part) => Elymus, Pascopyrum

Andropogon (in part) => Schizachyrium

Agrostis (in part) => Apera

Avena (in part) => Avenula

Deschampsia (in part) => Vahlodea

Diplachne => Leptochloa

Elymus (in part) => Leymus, Taeniatherum

Elytrigia => Elymus, Pascopyrum

Festuca (in part) => Lolium, Vulpia

Glyceria (in part) => Torreyochloa

Heleochloa => Crypsis

Helictotrichon => Avenula

Hierochloë => Anthoxanthum

Hystrix => Elymus

Leptoloma => Digitaria

Oryzopsis => Piptatherum

Panicum (in part) => Urochloa

Pseudosasa => Arundinaria

Puccinellia (in part) => Torreyochloa

Scleropoa => Desmazeria

Stipa => Piptochaetium

Triodia => Tridens

Trisetum (in part) => Sphenopholis

The following are taxa reported from our area in manuals, but no specimens seen:

Agrostis verticillata (Agrostis viridis, Polypogon viridis)

Ammophila arenaria

Apera interrupta

Aristida longespica (typical)

Avena barbata

Briza maxima

Bromus rubens

Calamagrostis perplexa

Danthonia sericea

Elymus hispidus subsp. barbulatus (Agropyron trichophorum)

Elymus trachycaulus subsp. subsecundus (Agropyron trachycaulum vars. ciliatum and unilaterale)

Eragrostis hirsuta

Hordeum brachyantherum

Hordeum gussoneanum (Hordeum hystrix)

Leptochloa uninervia

Muhlenbergia ramulosa (Sporobolus ramulosus)

Poa interior (P. nemoralis subsp. interior)

Poa secunda (P. nevadensis of Hitchcock & Chase (1951))

ACKNOWLEDGMENTS. We thank the curators and directors of the herbaria of Harvard University, the University of Maine, University of Massachusetts and the University of Vermont for allowing us access to their collections. We particularly appreciate the kindness of David Barrington, Chris Campbell and Karen Searcy for allowing use of the collections in their care outside of normal hours of operation. We are grateful also to Karen Searcy for allowing access to the notebooks of Harry E. Ahles at the University of Massachusetts and for checking some voucher specimens there. We also appreciate the check for voucher specimens by Steve Rawson, Cathy Paris, Janet Sullivan, Tom Vining, and Chris Campbell. Mary Barkworth graciously reviewed the manuscript and very generously provided updates for the nomenclature and taxonomy of several groups to bring them into agreement with the forthcoming Manual of Grasses for the Continental United States and Canada. Craig Greene provided additional useful information relating to Calamagrostis. Kancheepuram N. Gandhi generously gave assistance on some nomenclatural issues, but any errors in this work are the responsibility of the authors.