Vascular Flora of Concord, Massachusetts compiled by Ray Angelo ([email protected]) (first posted Dec. 30, 2012; last revised July 24, 2020) INTRODUCTION -- p. 1 FORMAT OF FLORA -- p. 4 REFERENCES -- p. 6 ACKNOWLEDGMENTS -- p. 9 FLORA LIST -- p. 10 APPENDIX A: Excluded records – p. 293 APPENDIX B: Species Introduced by Minot Pratt -- p. 294 APPENDIX C: Species Listed by Richard J. Eaton excluded here -- p. 297 APPENDIX D: Species Listed by Alfred W. Hosmer excluded here -- p. 300 APPENDIX E: Species Listed by Minot Pratt excluded here -- p. 306 APPENDIX F: Images of some William Brace pressed grass specimens -- p. 309 APPENDIX G: Other Voucher Images -- p. 317 APPENDIX H: Primary Concord botanists of the past -- p. 324 Presented here is perhaps the most complete and detailed list that has been compiled to date of the vascular plant species that have been verified as growing wild in Concord, Massachusetts. It is likely that Concord, Massachusetts is the most intensely botanized town in the United States for the longest period of time, starting with the brothers, Edward and Charles Jarvis in the 1820’s and 1830’s and continuing to the present day. Concord is endowed not only with a rich literary and historical heritage, but also with a wealth of habitats – three rivers, many ponds, brooks, meadows, bogs, swamps, marshes, deciduous-coniferous woodlands, open sand plains, fields, hills, ledges, and acidic as well as some circumneutral soils. It is situated close enough to the Atlantic coast to pick up elements of the coastal plain flora coming up from the south and far enough north and inland to pick up some elements of the boreal forest flora extending southward from northern New England. I am privileged to have been one of those amateur botanists who lived in Concord for some years with the free time to explore its natural treasures almost daily during that time. In that time I came to appreciate that even in a lifetime of daily botanizing it is not possible to know Concord’s diverse flora completely. Doubtless those worthier amateurs who preceded me in Concord came to realize this as well. These predecessors were Charles Jarvis (1800-26), Edward Jarvis (1803- 89), Henry D. Thoreau (1817-62), Sophia Thoreau (1819-71), Edward S. Hoar (1823-93), Minot Pratt (1805-78), Horace Mann, Jr. (1844-1868), Alfred W. Hosmer (1851-1903), Richard J. Eaton (1890-1976) and Laurence E. Richardson (1893-1985). In the decade or so that I botanized extensively in Concord I came away with the clear sense that I had barely scratched the surface of all that was there. Indeed, additional native species have been discovered recently in Concord in a very short period of time by William Brace during the late 1990s and early 2000s, and by Cole Winstanley in 2015-2016. As recently as 2019 a distinctive native species, Fallopia cilinodis, not known in Concord previously, was found on his first, brief botanizing trip here by Harvard botanist, Walter Kittredge. A hint of this understanding of the impossibility of grasping the depth and breadth of the flora of a township as varied as Concord is in Thoreau’s Journal entry for April 2, 1856, “It will take you half a lifetime to find out where to look for the earliest flower”, and in May 1853 when he comments, “how long some very conspicuous ones [flowers] may escape the most diligent walker, if you do not chance to visit their localities the right week or fortnight”. In his manuscript of the Plants of Concord Minot Pratt states for Ligustrum vulgare (Common Privet) “In 1871, I first found an old bush growing wild in the old rocky pasture near the Lime-kiln, within two rods of a path I had traveled hundreds of times for the previous 25 years.” See also my notes in this flora under the species Phegopteris connectilis and Castilleja coccinea for examples that point to how very difficult it is for any one person to know the flora of a township such as Concord, even with years of intensive botanizing. Those who came before me had the great advantage of a more open landscape in Concord that has become more difficult to traverse due to the reforestation of New England since the mid-19th century. In addition there has been much more development of the land, even since the late 1970s and early 1980s when I lived in Concord. Beautiful areas that I once explored are either destroyed or are no longer accessible due to no-trespass posting. Thoreau even foresaw such a time coming. In his essay “Walking” he comments, “At present, in this vicinity, the best part of the land is not private property; the landscape is not owned, and the walker enjoys comparative freedom. But possibly the day will come when it will be partitioned off into so-called pleasure grounds, in which a few will take a narrow and exclusive pleasure only, — when fences shall be multiplied, and man traps and other engines invented to confine men to the public road; and walking over the surface of God’s earth, shall be construed to mean trespassing on some gentleman’s grounds.” Fortunately, Concord has ample and varied conservation areas where many of its rare native plants remain hidden and protected. There is no question that the flora of Concord has changed since Thoreau’s time, due in large part to the reforestation and development just mentioned, but also to other factors such as the increase in alien species spread via the greater mobility of people and greater interaction with the world at large. Other significant factors would be changes in water quality, in air quality, in predation due to changing animal populations (including insects and especially deer), in pollination due to disappearance of pollinators, due to climate change, and perhaps other factors. To give some examples, Richard Eaton notes in his flora that in the 1930s the Concord rivers became significantly polluted with sewage. This had the consequence of reducing the acidity of the adjacent river meadows so that some species preferring acidic habitat that were formerly frequent in the meadows such as Sarracenia purpurea, Pogonia ophioglossoides, Platanthera psycodes and Arethusa bulbosa disappeared from these places and became limited to acidic habitat away from the rivers. Other species that prefer less acidic habitat such as Lemna minor became common or abundant in the rivers where they did not occur or were sparse before. The advent of deer in Concord in recent years would have an effect on the prevalence of some species in Liliaceae and Orchidaceae which deer have a preference for eating. Thoreau never mentions seeing deer in Concord in his Journal. I never saw one there in all my rambles in the 1970s and 1980s. I first saw one in Concord in 2007 on one of my few visits there since I left. Lastly, the warming of the climate will inevitably lead to some more northerly species near the southern limit of their range retreating from Concord such as Linnaea borealis, rare even in Thoreau’s time, now apparently gone. Correspondingly, species with more southerly ranges not previously occurring in Concord are likely to begin appearing here. See my article Angelo (2014). I am very thankful that I got to know Richard (“Dick”) Eaton (1890-1976) in the last year of his life, followed in his footsteps as Curator of Vascular Plants for the New England Botanical Club, shared with him the very beginnings of my finds in Concord, was treated to a lunch with him and his wife at his Cape Cod home, and had the honor (with the aid of his children) of writing a tribute to him for Rhodora, the journal of his beloved New England Botanical Club (Angelo 1987). It fascinated me when he told me that as a youngster in Concord he had shoveled snow for his neighbor, one of Thoreau’s best friends, the reclusive Ellery Channing. It was well within the realm of possibility that Thoreau could have lived long enough for the young Dick Eaton to have met him too. The survival in Concord of numerous plant populations from Thoreau’s time, many in the same localities where Thoreau, his successors and his predecessors saw them, offers the chance for us to become acquainted with other friends in Concord that Thoreau knew so well. Richard Eaton was one of the four botanizers who have left to us extensive written records detailing their experience of the flora of Concord and which, in addition to significant herbarium collections of two of these and of others, form the foundation of this present flora. Those other three are Minot Pratt (1805-1878), who left a lengthy manuscript on the plants of Concord to the Concord Free Public Library, Henry D. Thoreau (1817-1862), who left us his Journal the later years saturated with botanical notes some of which are yet unpublished, and Alfred W. Hosmer (1851-1903), who left to the Concord Free Public Library his voluminous notes on the flora of Concord andvicinity, particularly including flowering dates. All of these four but Pratt were born and raised in Concord. Collections of pressed herbarium specimens are vital to verifying records of occurrence since the mere naming of a species in a written account does not establish that the plant is correctly identified. Of the four notable botanizers above only Thoreau and Eaton made extensive collections of herbarium specimens. Both men studied and collected the difficult grasses and sedges of Concord, unlike Pratt and Hosmer. I cataloged the known specimen collections of Thoreau in 2019 and found there to be conservatively 1,503 collections (one or more specimens of the same taxon collected from the same site at the same time).