Early American botanists like John Torrey did not have to travel far afield to engage with the plant world—most of them were self-taught, and studied the plants growing near their homes. View some of the common plants Torrey studied so that you can look for them.
Canadian Horseweed (Conyza canadensis): In 1819 John Torrey attempted to identify as many plants as possible—native or otherwise—growing in the metropolitan area in A Catalogue of Plants, Growing Spontaneously within Thirty Miles of the City of New York. One plant, Canadian horseweed, could be found “in woods and among rocks.” It is a perennial (which means the plant lives for several growing seasons), and there have been accounts of this plant in the area as early as 1609. You can still find Canadian horseweed today in dry and exposed sunny sites like vacant lots and stone walls.
Conyza canadensis herbarium specimen. Collected by William C. Ferguson, 1930. William and Lynda Steere Herbarium, The New York Botanical Garden.
Conyza canadensis. Andrey Zharkikh from Salt Lake City, USA. Licensed under CC BY 2.0.
Timothy grass (Phleum pratense): There is no record of Timothy grass in the United States prior to 1711. It is likely that that this plant was accidentally introduced into the landscape from Europe. You can still find Timothy grass today in minimally maintained grasslands, meadow areas and along roadsides. In rural areas it is used as hay and to feed livestock.
Phleum pretense L.herbarium specimen. Collected by George Nash. William and Lynda Steere Herbarium, The New York Botanical Garden.
Phleum pretense L.. I, Hugo.arg. Licensed under CC BY-SA 3.0.
Yellow Toadflax (Linaria vulgaris): Yellow toadflax (Linaria vulgaris) or “Bastard toad-flax” as Torrey called it, was a problem even in the 19th century. John Bartram [BG1] was the first to report the plant in North America in 1759, stating, “ye stinking yellow linarya is ye most hurtful plant in our pastures that can grow in our Northern climate. Neither a spade plow nor hoe can destroy it…” Today yellow toadflax populates vacant lots, urban meadows, and even small pavement openings and cracks.
Linaria vulgaris herbarium specimen. Collected by H. Gillman, 1945. William and Lynda Steere Herbarium, The New York Botanical Garden.
Linaria vulgaris. Nicholas A. Tonelli from Northeast Pennsylvania, USA. Licensed under CC BY 2.0.
Common Buckthorn (Rhamnus cathartica): While some introduced plants exist comfortably with other plants in New York, others are determined to take over. Plants that are seen as harmful to local plants are called invasive. Common buckthorn (Rhamnus cathartica), is one such plant. Introduced from Europe in the 1700s for its medicinal properties and as a hedging material, it has now become a nuisance. Buckthorn degrades wildlife habitats and out-competes native plants for water, nutrients, and light.
Rhamnus cathartica herbarium specimen. Collected by M. Nee, 2013. William and Lynda Steere Herbarium, The New York Botanical Garden.
Rhamnus cathartica. Robert Flogaus-Faust. Licensed under CC BY 4.0.
With the support of the National Endowment for the Humanities, The New York Botanical Garden is working to make the letters of John Torrey available to larger audiences. Letters to Torrey by over 350 different correspondents are being digitized, transcribed, and made searchable online in the Biodiversity Heritage Library.
Image: Letter from William Brackenridge to John Torrey, September 6, 1847. Manuscript. LuEsther T. Mertz Library, The New York Botanical Garden.
A project of The New York Botanical Garden, the New York City EcoFlora project engages the public in the protection and preservation of the City’s native plant species. Participants assemble data on the City’s flora to assist in informing policy decisions about management and conservation.