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1927 Map of the Arboretum

Spontaneous Flora at the Arnold Arboretum

Glory of the snow (Chionodoxa luciliae)
Glory of the snow (Chionodoxa luciliae)

Much of what is now the Arnold Arboretum was once part of Benjamin Bussey’s farm (until 1842), and before that the ground had been farmed by Eleazer Weld. In 1692, a small saw mill operated along the banks of Bussey Brook at the base of Hemlock Hill, turning virgin timber into lumber. In other words, the land comprising the Arboretum has a land-use history going back some two hundred years before the Arboretum was established.The spontaneous vegetation that exists here today—which is defined as any plant that grows in an area without assistance from humans—reflects not only the agricultural history of the land but also its long horticultural history.

It includes species native to a variety of New England habitats, and species from Europe that were brought here during the colonial period for medicinal, ornamental or agricultural purposes (along with “weedy” species that contaminated their seed). There are also a number of species from Asia, mainly woody and originally planted for landscape purposes, that managed to escape from cultivation and spread throughout the area by various means of dispersal (e.g., wind, water, animal). In short, the Arboretum’s spontaneous vegetation is a cosmopolitan mix of species that reflects the complex social and ecological history of the land itself.

The Herbarium of Cultivated Plants at the Arnold Arboretum houses a collection of herbarium specimens called the Spontaneous Flora. Find more information on this collection here.

Flowering Plants

Monilophytes (ferns and horsetails)



Photo Gallery

Further reading

  • Del Tredici, P. 2010. Excerpts from Wild Urban Plants of the Northeast. Arnoldia 68(1): 13-25 [pdf]
  • Dalton, P.A., Novelo, A.R. 1983. Aquatic and Wetland Plants of the Arboretum Arnoldia 43(2): 7-44. [pdf]
  • Green, P.S. 1962. Herbaceous Aliens in the Arboretum. Bulletin of Popular Information 22(7): 49-56. [pdf]
  • Palmer, E.J. 1930. The spontaneous flora of the Arnold Arboretum. Journal of the Arnold Arboretum 11: 63-119. [pdf]
  • Palmer, E.J. 1935. Supplement to the spontaneous flora of the Arnold Arboretum. Journal of the Arnold Arboretum 16: 81-87. [pdf]
  • Palmer, E.J. 1947. Second supplement to the spontaneous flora of the Arnold Arboretum. Journal of the Arnold Arboretum 28: 410-418. [pdf]
  • Sargent, C.S. 1874. Report of the Director of the Arnold Arboretum (Republished in Palmer, 1930).
  • Del Tredici, P. Spontaneous Urban Vegetation: Reflections of Change in a Globalized World. Nature and Culture 5(3), Winter 2010: 299–315 [pdf]
  • Hetman, J. The Weeds and the Wilderness: An Interview with Les Mehrhoff on the Spontaneous Flora of the Arnold Arboretum. Silva, Fall/Winter 2008-2009: 2-3. [pdf]

Monilophytes (ferns and horsetails)

List compiled by Don Lubin and Arboretum staff.


  • Lady fern (Athyrium filix-femina)
  • Interrupted fern (Claytosmunda claytoniana)
  • Hayscented fern (Dennstaedtia punctilobula)
  • Intermediate wood fern (Dryopteris intermedia)
  • Spinulose fern (Dryopteris carthusiana)
  • Horsetail (Equisetum arvense)*
  • Ostrich fern (Matteuccia struthiopteris)
  • Sensitive fern (Onoclea sensibilis)
  • Cinnamon fern (Osmundastrum cinnamomea)
  • Royal fern (Osmunda regalis)
  • Appalachian polypody (Polypodium appalachianum)*
  • New York Fern (Parathelypteris noveboracensis)
  • Bracken fern (Pteridium aquilinum)

All except (*) occur between Bussey Brook and Hemlock Hill.

Related Articles & Resources

  • PPG I. “A community‐derived classification for extant lycophytes and ferns.” Journal of Systematics and Evolution 54.6 (2016): 563-603.
  • Pteridophytes of North America, Flora of North America
  • Angelo, R. 1985. Thoreau’s Climbing Fern Rediscovered. Arnoldia 45(3): 24-26. [pdf]


List compiled by Arboretum staff.

  • Black knot fungus (Apiosporina morbosa)
  • Yellow patches fungus (Amanitas flavoconia)^
  • Tawny grisette (Amanitas fulva)^
  • Grisette (Amanitas vaginata)^
  • Red chantrelle (Cantherellus cinnabarinus)
  • Shaggy mane mushroom (Coprinus comatus)
  • Bird’s nest fungus (Crucibulum spp. and Cyathus spp.)
  • Thin maze fungus (Daedaleopsis confragosa)^
  • Fomes fomentarius^
  • Dog vomit slime mold (Fuligo septica)
  • Artist’s conk (Ganoderma applanatum)^
  • Hemlock varnish shelf (Ganoderma tsugae)^
  • Hen of the woods (Grifola frondosa)
  • Lactarius hygrophoroides^
  • Chicken of the woods (Laetiporus sulphureus)
  • Indian pipe or ghost pipe (Monotropa uniflora)
  • Bark mycena (Mycena spp.)
  • Mower’s mushroom (Panaeolus foenisecii)^
  • Luminescent pan or bitter oyster (Panellus stipticus)^
  • Dryer’s (Phaeolus schweinitzii)^
  • Common oyster mushroom (Pleurotus ostreatus)
  • Pheasant’s-back polypore or dryad’s saddle (Polyporus squamosus)
  • Stinky squid (Pseudocolus fusiformis)
  • Crusty russula (Russula crustose)^
  • Red fungus (Russula sp.)^
  • Burgundy mushroom or wine cap (Stropharia rugosoannulata)^
  • Tuber arnoldianum
  • Turkey tail (Trametes versicolor)^
  • Witch’s butter (Tremella mesenterica)
  • Violet tooth (Trichaptum biforme)^
  • Bitter bolete or bitter tylopilus (Tylopilus felleus)^
  • White cheese (Tyromyces chioneus)^

^Found on a mushroom foray sponsored by the Arboretum and the Boston Mycological Club in late June 2018.

Related Articles & Resources

  • Healy, R. 2014. Reading Tree Roots for Clues: The Habits of Truffles and Other Ectomycorrhizal Cup Fungi. Arnoldia 72 (2): 33-39. [pdf]
  • Richardson, K. 2009. A Closer Look at Fungi in the Arnold Arboretum. Arnoldia 66 (4): 13-21. [pdf]
  • Reed, C. “Don’t Eat Amanitas.” Harvard Magazine September-October 2010: 72. [pdf]


List compiled by Steve Schneider, Director of Operations, using a line-transect survey method on Peters Hill.

  • Mealy rosette (Physcia millegrana)
  • Greenshield (Flavoparmelia caperata)
  • Candle flame (Candelaria concolor)
  • Punctelia rudecta
  • Punctelia subrudecta
  • Cup lichen (Cladonia macileata)
  • Stilling’s disc (Buellia stillingiana)

Related Articles & Resources

  • Weaver R.E. 1975. Lichens: Mysterious and Diverse. Arnolida 35(3): 133-159. (pdf)
  • Raup, H.M. 1933. Lichens. Bulletin of Popular Information no 3, March 15, 1933. (pdf)

Jerusalem artichoke (Helianthus tuberosus)
Hedge bindweed (Calystegia sepium)
Fase Solomon's seal (Maianthemum racemosum)
Evening primrose (Oenothera longissima)
St. John's wort (Hypericum perforatum)
Chickory (Cichorium intybus)
Butter & eggs (Linaria vulgaris)
Common burdock (Arctium minus)
Wild geranium (Geranium maculatum)
Trillium (Trillium)
Tansy (*i*Tanacetum vulgare*/i*)
Tall meadow rue (Thalictrum pubescens)
Squirrel corn (Dicentra canadensis)
Spotted Joe-Pye weed (Eutrochium maculatum)
Eastern skunk cabbage (Symplocarpus foetidus)
Queen Anne's lace (Daucus carota)
Purple loosestrife (Lythrum salicaria)
Pickerelweed (Pontederia cordata)
Pearly everlasting (Anaphalis margaritacea)
Orange hawkweed (Pilosella aurantiaca)
New England aster (Symphyotrichum novae-angliae)
Common milkweed (Asclepias syriaca)
Marsh marigold (Caltha palustris)
Spotted jewelweed (Impatiens capensis)